diff --git a/src/command/cmd_ac.c b/src/command/cmd_ac.c
index 6e22e90e..3aeedc60 100644
--- a/src/command/cmd_ac.c
+++ b/src/command/cmd_ac.c
@@ -1635,7 +1635,6 @@ cmd_ac_complete_filepath(const char* const input, char* const startstr, gboolean
 static char*
 _cmd_ac_complete_params(ProfWin* window, const char* const input, gboolean previous)
 {
-    int i;
     char* result = NULL;
 
     jabber_conn_status_t conn_status = connection_get_status();
@@ -1644,7 +1643,7 @@ _cmd_ac_complete_params(ProfWin* window, const char* const input, gboolean previ
     gchar* boolean_choices[] = { "/beep", "/intype", "/states", "/outtype", "/flash", "/splash",
                                  "/history", "/vercheck", "/privileges", "/wrap", "/carbons", "/os", "/slashguard" };
 
-    for (i = 0; i < ARRAY_SIZE(boolean_choices); i++) {
+    for (int i = 0; i < ARRAY_SIZE(boolean_choices); i++) {
         result = autocomplete_param_with_func(input, boolean_choices[i], prefs_autocomplete_boolean_choice, previous, NULL);
         if (result) {
             return result;
@@ -1661,7 +1660,7 @@ _cmd_ac_complete_params(ProfWin* window, const char* const input, gboolean previ
 
             // Remove quote character before and after names when doing autocomplete
             char* unquoted = strip_arg_quotes(input);
-            for (i = 0; i < ARRAY_SIZE(nick_choices); i++) {
+            for (int i = 0; i < ARRAY_SIZE(nick_choices); i++) {
                 result = autocomplete_param_with_ac(unquoted, nick_choices[i], nick_ac, TRUE, previous);
                 if (result) {
                     free(unquoted);
@@ -1676,7 +1675,7 @@ _cmd_ac_complete_params(ProfWin* window, const char* const input, gboolean previ
         gchar* contact_choices[] = { "/msg", "/info" };
         // Remove quote character before and after names when doing autocomplete
         char* unquoted = strip_arg_quotes(input);
-        for (i = 0; i < ARRAY_SIZE(contact_choices); i++) {
+        for (int i = 0; i < ARRAY_SIZE(contact_choices); i++) {
             result = autocomplete_param_with_func(unquoted, contact_choices[i], roster_contact_autocomplete, previous, NULL);
             if (result) {
                 free(unquoted);
@@ -1686,7 +1685,7 @@ _cmd_ac_complete_params(ProfWin* window, const char* const input, gboolean previ
         free(unquoted);
 
         gchar* resource_choices[] = { "/caps", "/ping" };
-        for (i = 0; i < ARRAY_SIZE(resource_choices); i++) {
+        for (int i = 0; i < ARRAY_SIZE(resource_choices); i++) {
             result = autocomplete_param_with_func(input, resource_choices[i], roster_fulljid_autocomplete, previous, NULL);
             if (result) {
                 return result;
@@ -1695,7 +1694,7 @@ _cmd_ac_complete_params(ProfWin* window, const char* const input, gboolean previ
     }
 
     gchar* invite_choices[] = { "/join" };
-    for (i = 0; i < ARRAY_SIZE(invite_choices); i++) {
+    for (int i = 0; i < ARRAY_SIZE(invite_choices); i++) {
         result = autocomplete_param_with_func(input, invite_choices[i], muc_invites_find, previous, NULL);
         if (result) {
             return result;
@@ -1705,7 +1704,7 @@ _cmd_ac_complete_params(ProfWin* window, const char* const input, gboolean previ
     gchar* cmds[] = { "/prefs", "/disco", "/room", "/autoping", "/mainwin", "/inputwin" };
     Autocomplete completers[] = { prefs_ac, disco_ac, room_ac, autoping_ac, winpos_ac, winpos_ac };
 
-    for (i = 0; i < ARRAY_SIZE(cmds); i++) {
+    for (int i = 0; i < ARRAY_SIZE(cmds); i++) {
         result = autocomplete_param_with_ac(input, cmds[i], completers[i], TRUE, previous);
         if (result) {
             return result;
@@ -1778,7 +1777,7 @@ _cmd_ac_complete_params(ProfWin* window, const char* const input, gboolean previ
 
     int len = strlen(input);
     char parsed[len + 1];
-    i = 0;
+    int i = 0;
     while (i < len) {
         if (input[i] == ' ') {
             break;
@@ -1856,12 +1855,11 @@ _who_autocomplete(ProfWin* window, const char* const input, gboolean previous)
     } else {
         jabber_conn_status_t conn_status = connection_get_status();
         if (conn_status == JABBER_CONNECTED) {
-            int i = 0;
             gchar* group_commands[] = { "/who any", "/who online", "/who offline",
                                         "/who chat", "/who away", "/who xa", "/who dnd", "/who available",
                                         "/who unavailable" };
 
-            for (i = 0; i < ARRAY_SIZE(group_commands); i++) {
+            for (int i = 0; i < ARRAY_SIZE(group_commands); i++) {
                 result = autocomplete_param_with_func(input, group_commands[i], roster_group_autocomplete, previous, NULL);
                 if (result) {
                     return result;
@@ -2186,7 +2184,6 @@ _bookmark_autocomplete(ProfWin* window, const char* const input, gboolean previo
 static char*
 _notify_autocomplete(ProfWin* window, const char* const input, gboolean previous)
 {
-    int i = 0;
     char* result = NULL;
 
     result = autocomplete_param_with_func(input, "/notify room trigger remove", prefs_autocomplete_room_trigger, previous, NULL);
@@ -2196,7 +2193,7 @@ _notify_autocomplete(ProfWin* window, const char* const input, gboolean previous
 
     gchar* boolean_choices1[] = { "/notify room current", "/notify chat current", "/notify typing current",
                                   "/notify room text", "/notify chat text" };
-    for (i = 0; i < ARRAY_SIZE(boolean_choices1); i++) {
+    for (int i = 0; i < ARRAY_SIZE(boolean_choices1); i++) {
         result = autocomplete_param_with_func(input, boolean_choices1[i], prefs_autocomplete_boolean_choice, previous, NULL);
         if (result) {
             return result;
@@ -2229,7 +2226,7 @@ _notify_autocomplete(ProfWin* window, const char* const input, gboolean previous
     }
 
     gchar* boolean_choices2[] = { "/notify invite", "/notify sub", "/notify mention", "/notify trigger" };
-    for (i = 0; i < ARRAY_SIZE(boolean_choices2); i++) {
+    for (int i = 0; i < ARRAY_SIZE(boolean_choices2); i++) {
         result = autocomplete_param_with_func(input, boolean_choices2[i], prefs_autocomplete_boolean_choice, previous, NULL);
         if (result) {
             return result;
@@ -3713,12 +3710,11 @@ _account_autocomplete(ProfWin* window, const char* const input, gboolean previou
         return found;
     }
 
-    int i = 0;
     gchar* account_choice[] = { "/account set", "/account show", "/account enable",
                                 "/account disable", "/account rename", "/account clear", "/account remove",
                                 "/account default set" };
 
-    for (i = 0; i < ARRAY_SIZE(account_choice); i++) {
+    for (int i = 0; i < ARRAY_SIZE(account_choice); i++) {
         found = autocomplete_param_with_func(input, account_choice[i], accounts_find_all, previous, NULL);
         if (found) {
             return found;
diff --git a/src/command/cmd_defs.c b/src/command/cmd_defs.c
index 8bfd33d3..53c42bae 100644
--- a/src/command/cmd_defs.c
+++ b/src/command/cmd_defs.c
@@ -2557,17 +2557,16 @@ _cmd_index(Command* cmd)
     index_source = g_string_append(index_source, " ");
 
     int len = g_strv_length(cmd->help.tags);
-    int i = 0;
-    for (i = 0; i < len; i++) {
+    for (int i = 0; i < len; i++) {
         index_source = g_string_append(index_source, cmd->help.tags[i]);
         index_source = g_string_append(index_source, " ");
     }
     len = g_strv_length(cmd->help.synopsis);
-    for (i = 0; i < len; i++) {
+    for (int i = 0; i < len; i++) {
         index_source = g_string_append(index_source, cmd->help.synopsis[i]);
         index_source = g_string_append(index_source, " ");
     }
-    for (i = 0; cmd->help.args[i][0] != NULL; i++) {
+    for (int i = 0; cmd->help.args[i][0] != NULL; i++) {
         index_source = g_string_append(index_source, cmd->help.args[i][0]);
         index_source = g_string_append(index_source, " ");
         index_source = g_string_append(index_source, cmd->help.args[i][1]);
@@ -2578,7 +2577,7 @@ _cmd_index(Command* cmd)
     g_string_free(index_source, TRUE);
 
     GString* index = g_string_new("");
-    for (i = 0; i < g_strv_length(tokens); i++) {
+    for (int i = 0; i < g_strv_length(tokens); i++) {
         index = g_string_append(index, tokens[i]);
         index = g_string_append(index, " ");
     }
@@ -2598,8 +2597,7 @@ cmd_search_index_any(char* term)
     gchar** processed_terms = g_str_tokenize_and_fold(term, NULL, NULL);
     int terms_len = g_strv_length(processed_terms);
 
-    int i = 0;
-    for (i = 0; i < terms_len; i++) {
+    for (int i = 0; i < terms_len; i++) {
         GList* index_keys = g_hash_table_get_keys(search_index);
         GList* curr = index_keys;
         while (curr) {
@@ -2630,8 +2628,7 @@ cmd_search_index_all(char* term)
     while (curr) {
         char* command = curr->data;
         int matches = 0;
-        int i = 0;
-        for (i = 0; i < terms_len; i++) {
+        for (int i = 0; i < terms_len; i++) {
             char* command_index = g_hash_table_lookup(search_index, command);
             if (g_str_match_string(terms[i], command_index, FALSE)) {
                 matches++;
@@ -2663,8 +2660,7 @@ cmd_init(void)
 
     // load command defs into hash table
     commands = g_hash_table_new(g_str_hash, g_str_equal);
-    unsigned int i;
-    for (i = 0; i < ARRAY_SIZE(command_defs); i++) {
+    for (unsigned int i = 0; i < ARRAY_SIZE(command_defs); i++) {
         Command* pcmd = command_defs + i;
 
         // add to hash
@@ -2738,8 +2734,7 @@ cmd_get_ordered(const char* const tag)
 static gboolean
 _cmd_has_tag(Command* pcmd, const char* const tag)
 {
-    int i = 0;
-    for (i = 0; pcmd->help.tags[i] != NULL; i++) {
+    for (int i = 0; pcmd->help.tags[i] != NULL; i++) {
         if (g_strcmp0(tag, pcmd->help.tags[i]) == 0) {
             return TRUE;
         }
@@ -2758,8 +2753,8 @@ void
 command_docgen(void)
 {
     GList* cmds = NULL;
-    unsigned int i;
-    for (i = 0; i < ARRAY_SIZE(command_defs); i++) {
+
+    for (unsigned int i = 0; i < ARRAY_SIZE(command_defs); i++) {
         Command* pcmd = command_defs + i;
         cmds = g_list_insert_sorted(cmds, pcmd, (GCompareFunc)_cmp_command);
     }
diff --git a/src/command/cmd_funcs.c b/src/command/cmd_funcs.c
index 56a68297..0837f630 100644
--- a/src/command/cmd_funcs.c
+++ b/src/command/cmd_funcs.c
@@ -1086,8 +1086,7 @@ _writecsv(int fd, const char* const str)
     size_t len = strlen(str);
     char* s = malloc(2 * len * sizeof(char));
     char* c = s;
-    int i = 0;
-    for (; i < strlen(str); i++) {
+    for (int i =0; i < strlen(str); i++) {
         if (str[i] != '"')
             *c++ = str[i];
         else {
@@ -1415,8 +1414,7 @@ cmd_close(ProfWin* window, const char* const command, gchar** args)
     gboolean is_num = TRUE;
     int index = 0;
     if (args[0] != NULL) {
-        int i = 0;
-        for (i = 0; i < strlen(args[0]); i++) {
+        for (int i = 0; i < strlen(args[0]); i++) {
             if (!isdigit((int)args[0][i])) {
                 is_num = FALSE;
                 break;
@@ -1503,8 +1501,7 @@ gboolean
 cmd_win(ProfWin* window, const char* const command, gchar** args)
 {
     gboolean is_num = TRUE;
-    int i = 0;
-    for (i = 0; i < strlen(args[0]); i++) {
+    for (int i = 0; i < strlen(args[0]); i++) {
         if (!isdigit((int)args[0][i])) {
             is_num = FALSE;
             break;
@@ -8567,14 +8564,13 @@ cmd_omemo_fingerprint(ProfWin* window, const char* const command, gchar** args)
     }
 
     GList* fingerprints = omemo_known_device_identities(jid->barejid);
-    GList* fingerprint;
 
     if (!fingerprints) {
         win_println(window, THEME_DEFAULT, "-", "There is no known fingerprints for %s", jid->barejid);
         return TRUE;
     }
 
-    for (fingerprint = fingerprints; fingerprint != NULL; fingerprint = fingerprint->next) {
+    for (GList* fingerprint = fingerprints; fingerprint != NULL; fingerprint = fingerprint->next) {
         char* formatted_fingerprint = omemo_format_fingerprint(fingerprint->data);
         gboolean trusted = omemo_is_trusted_identity(jid->barejid, fingerprint->data);
 
@@ -8710,8 +8706,7 @@ cmd_omemo_untrust(ProfWin* window, const char* const command, gchar** args)
     omemo_untrust(barejid, fingerprint);
 
     char* unformatted_fingerprint = malloc(strlen(fingerprint));
-    int i;
-    int j;
+    int i, j;
     for (i = 0, j = 0; fingerprint[i] != '\0'; i++) {
         if (!g_ascii_isxdigit(fingerprint[i])) {
             continue;
diff --git a/src/common.c b/src/common.c
index f05bc3ba..c0bd6525 100644
--- a/src/common.c
+++ b/src/common.c
@@ -91,10 +91,9 @@ create_dir(char* name)
 gboolean
 mkdir_recursive(const char* dir)
 {
-    int i;
     gboolean result = TRUE;
 
-    for (i = 1; i <= strlen(dir); i++) {
+    for (int i = 1; i <= strlen(dir); i++) {
         if (dir[i] == '/' || dir[i] == '\0') {
             gchar* next_dir = g_strndup(dir, i);
             result = create_dir(next_dir);
@@ -446,8 +445,7 @@ get_random_string(int length)
 
     prng = g_rand_new();
 
-    int i;
-    for (i = 0; i < length; i++) {
+    for (int i = 0; i < length; i++) {
         rand[i] = alphabet[g_rand_int_range(prng, 0, sizeof(alphabet))];
     }
     g_rand_free(prng);
diff --git a/src/config/accounts.c b/src/config/accounts.c
index 3787d889..88828da9 100644
--- a/src/config/accounts.c
+++ b/src/config/accounts.c
@@ -77,8 +77,7 @@ accounts_load(void)
     gsize naccounts;
     gchar** account_names = g_key_file_get_groups(accounts, &naccounts);
 
-    gsize i;
-    for (i = 0; i < naccounts; i++) {
+    for (gsize i = 0; i < naccounts; i++) {
         autocomplete_add(all_ac, account_names[i]);
         if (g_key_file_get_boolean(accounts, account_names[i], "enabled", NULL)) {
             autocomplete_add(enabled_ac, account_names[i]);
@@ -252,8 +251,7 @@ accounts_get_account(const char* const name)
         GList* otr_manual = NULL;
         gchar** manual = g_key_file_get_string_list(accounts, name, "otr.manual", &length, NULL);
         if (manual) {
-            int i;
-            for (i = 0; i < length; i++) {
+            for (int i = 0; i < length; i++) {
                 otr_manual = g_list_append(otr_manual, strdup(manual[i]));
             }
             g_strfreev(manual);
@@ -262,8 +260,7 @@ accounts_get_account(const char* const name)
         GList* otr_opportunistic = NULL;
         gchar** opportunistic = g_key_file_get_string_list(accounts, name, "otr.opportunistic", &length, NULL);
         if (opportunistic) {
-            int i;
-            for (i = 0; i < length; i++) {
+            for (int i = 0; i < length; i++) {
                 otr_opportunistic = g_list_append(otr_opportunistic, strdup(opportunistic[i]));
             }
             g_strfreev(opportunistic);
@@ -272,8 +269,7 @@ accounts_get_account(const char* const name)
         GList* otr_always = NULL;
         gchar** always = g_key_file_get_string_list(accounts, name, "otr.always", &length, NULL);
         if (always) {
-            int i;
-            for (i = 0; i < length; i++) {
+            for (int i = 0; i < length; i++) {
                 otr_always = g_list_append(otr_always, strdup(always[i]));
             }
             g_strfreev(always);
@@ -287,8 +283,7 @@ accounts_get_account(const char* const name)
         GList* omemo_enabled = NULL;
         gchar** enabled_list = g_key_file_get_string_list(accounts, name, "omemo.enabled", &length, NULL);
         if (enabled_list) {
-            int i;
-            for (i = 0; i < length; i++) {
+            for (int i = 0; i < length; i++) {
                 omemo_enabled = g_list_append(omemo_enabled, strdup(enabled_list[i]));
             }
             g_strfreev(enabled_list);
@@ -297,8 +292,7 @@ accounts_get_account(const char* const name)
         GList* omemo_disabled = NULL;
         gchar** disabled_list = g_key_file_get_string_list(accounts, name, "omemo.disabled", &length, NULL);
         if (disabled_list) {
-            int i;
-            for (i = 0; i < length; i++) {
+            for (int i = 0; i < length; i++) {
                 omemo_disabled = g_list_append(omemo_disabled, strdup(disabled_list[i]));
             }
             g_strfreev(disabled_list);
@@ -425,8 +419,7 @@ accounts_rename(const char* const account_name, const char* const new_name)
         "tls.policy"
     };
 
-    int i;
-    for (i = 0; i < ARRAY_SIZE(string_keys); i++) {
+    for (int i = 0; i < ARRAY_SIZE(string_keys); i++) {
         char* value = g_key_file_get_string(accounts, account_name, string_keys[i], NULL);
         if (value) {
             g_key_file_set_string(accounts, new_name, string_keys[i], value);
diff --git a/src/config/color.c b/src/config/color.c
index 63089fd8..7fca0d1a 100644
--- a/src/config/color.c
+++ b/src/config/color.c
@@ -343,12 +343,11 @@ color_distance(const struct color_def* a, const struct color_def* b)
 static int
 find_closest_col(int h, int s, int l)
 {
-    int i;
     struct color_def a = { h, s, l };
     int min = 0;
     int dmin = color_distance(&a, &color_names[0]);
 
-    for (i = 1; i < COLOR_NAME_SIZE; i++) {
+    for (int i = 1; i < COLOR_NAME_SIZE; i++) {
         int d = color_distance(&a, &color_names[i]);
         if (d < dmin) {
             dmin = d;
@@ -361,7 +360,6 @@ find_closest_col(int h, int s, int l)
 static int
 find_col(const char* col_name, int n)
 {
-    int i;
     char name[32] = { 0 };
 
     /*
@@ -381,7 +379,7 @@ find_col(const char* col_name, int n)
         return -1;
     }
 
-    for (i = 0; i < COLOR_NAME_SIZE; i++) {
+    for (int i = 0; i < COLOR_NAME_SIZE; i++) {
         if (g_ascii_strcasecmp(name, color_names[i].name) == 0) {
             return i;
         }
@@ -462,8 +460,6 @@ color_pair_cache_reset(void)
 static int
 _color_pair_cache_get(int fg, int bg)
 {
-    int i;
-
     if (COLORS < 256) {
         if (fg > 7 || bg > 7) {
             log_error("Color: trying to load 256 colour theme without capable terminal");
@@ -472,7 +468,7 @@ _color_pair_cache_get(int fg, int bg)
     }
 
     /* try to find pair in cache */
-    for (i = 0; i < cache.size; i++) {
+    for (int i = 0; i < cache.size; i++) {
         if (fg == cache.pairs[i].fg && bg == cache.pairs[i].bg) {
             return i;
         }
@@ -486,7 +482,7 @@ _color_pair_cache_get(int fg, int bg)
         return -1;
     }
 
-    i = cache.size;
+    int i = cache.size;
     cache.pairs[i].fg = fg;
     cache.pairs[i].bg = bg;
     /* (re-)define the new pair in curses */
diff --git a/src/config/preferences.c b/src/config/preferences.c
index 00a1e5ce..e4aebdb5 100644
--- a/src/config/preferences.c
+++ b/src/config/preferences.c
@@ -194,8 +194,7 @@ _prefs_load(void)
     gsize len = 0;
     gchar** triggers = g_key_file_get_string_list(prefs, PREF_GROUP_NOTIFICATIONS, "room.trigger.list", &len, NULL);
 
-    int i = 0;
-    for (i = 0; i < len; i++) {
+    for (int i = 0; i < len; i++) {
         autocomplete_add(room_trigger_ac, triggers[i]);
     }
     g_strfreev(triggers);
@@ -312,14 +311,15 @@ prefs_message_get_triggers(const char* const message)
     char* message_lower = g_utf8_strdown(message, -1);
     gsize len = 0;
     gchar** triggers = g_key_file_get_string_list(prefs, PREF_GROUP_NOTIFICATIONS, "room.trigger.list", &len, NULL);
-    int i;
-    for (i = 0; i < len; i++) {
+
+    for (int i = 0; i < len; i++) {
         char* trigger_lower = g_utf8_strdown(triggers[i], -1);
         if (g_strrstr(message_lower, trigger_lower)) {
             result = g_list_append(result, strdup(triggers[i]));
         }
         g_free(trigger_lower);
     }
+
     g_strfreev(triggers);
     g_free(message_lower);
 
@@ -1384,8 +1384,7 @@ prefs_get_room_notify_triggers(void)
     gsize len = 0;
     gchar** triggers = g_key_file_get_string_list(prefs, PREF_GROUP_NOTIFICATIONS, "room.trigger.list", &len, NULL);
 
-    int i;
-    for (i = 0; i < len; i++) {
+    for (int i = 0; i < len; i++) {
         result = g_list_append(result, strdup(triggers[i]));
     }
 
@@ -1476,8 +1475,7 @@ prefs_titlebar_pos_up(void)
 {
     ProfWinPlacement* placement = prefs_get_win_placement();
 
-    int pos = 2;
-    for (pos = 2; pos < 5; pos++) {
+    for (int pos = 2; pos < 5; pos++) {
         if (placement->titlebar_pos == pos) {
             placement->titlebar_pos = pos - 1;
 
@@ -1504,8 +1502,7 @@ prefs_mainwin_pos_up(void)
 {
     ProfWinPlacement* placement = prefs_get_win_placement();
 
-    int pos = 2;
-    for (pos = 2; pos < 5; pos++) {
+    for (int pos = 2; pos < 5; pos++) {
         if (placement->mainwin_pos == pos) {
             placement->mainwin_pos = pos - 1;
 
@@ -1532,8 +1529,7 @@ prefs_statusbar_pos_up(void)
 {
     ProfWinPlacement* placement = prefs_get_win_placement();
 
-    int pos = 2;
-    for (pos = 2; pos < 5; pos++) {
+    for (int pos = 2; pos < 5; pos++) {
         if (placement->statusbar_pos == pos) {
             placement->statusbar_pos = pos - 1;
 
@@ -1560,8 +1556,7 @@ prefs_inputwin_pos_up(void)
 {
     ProfWinPlacement* placement = prefs_get_win_placement();
 
-    int pos = 2;
-    for (pos = 2; pos < 5; pos++) {
+    for (int pos = 2; pos < 5; pos++) {
         if (placement->inputwin_pos == pos) {
             placement->inputwin_pos = pos - 1;
 
@@ -1588,8 +1583,7 @@ prefs_titlebar_pos_down(void)
 {
     ProfWinPlacement* placement = prefs_get_win_placement();
 
-    int pos = 1;
-    for (pos = 1; pos < 4; pos++) {
+    for (int pos = 1; pos < 4; pos++) {
         if (placement->titlebar_pos == pos) {
             placement->titlebar_pos = pos + 1;
 
@@ -1616,8 +1610,7 @@ prefs_mainwin_pos_down(void)
 {
     ProfWinPlacement* placement = prefs_get_win_placement();
 
-    int pos = 1;
-    for (pos = 1; pos < 4; pos++) {
+    for (int pos = 1; pos < 4; pos++) {
         if (placement->mainwin_pos == pos) {
             placement->mainwin_pos = pos + 1;
 
@@ -1644,8 +1637,7 @@ prefs_statusbar_pos_down(void)
 {
     ProfWinPlacement* placement = prefs_get_win_placement();
 
-    int pos = 1;
-    for (pos = 1; pos < 4; pos++) {
+    for (int pos = 1; pos < 4; pos++) {
         if (placement->statusbar_pos == pos) {
             placement->statusbar_pos = pos + 1;
 
@@ -1672,8 +1664,7 @@ prefs_inputwin_pos_down(void)
 {
     ProfWinPlacement* placement = prefs_get_win_placement();
 
-    int pos = 1;
-    for (pos = 1; pos < 4; pos++) {
+    for (int pos = 1; pos < 4; pos++) {
         if (placement->inputwin_pos == pos) {
             placement->inputwin_pos = pos + 1;
 
@@ -1741,8 +1732,8 @@ prefs_get_aliases(void)
         GList* result = NULL;
         gsize len;
         gchar** keys = g_key_file_get_keys(prefs, PREF_GROUP_ALIAS, &len, NULL);
-        int i;
-        for (i = 0; i < len; i++) {
+
+        for (int i = 0; i < len; i++) {
             char* name = keys[i];
             char* value = g_key_file_get_string(prefs, PREF_GROUP_ALIAS, name, NULL);
 
diff --git a/src/config/tlscerts.c b/src/config/tlscerts.c
index 6b4d759f..55a3fa1b 100644
--- a/src/config/tlscerts.c
+++ b/src/config/tlscerts.c
@@ -71,8 +71,7 @@ tlscerts_init(void)
     gsize len = 0;
     gchar** groups = g_key_file_get_groups(tlscerts, &len);
 
-    int i = 0;
-    for (i = 0; i < g_strv_length(groups); i++) {
+    for (int i = 0; i < g_strv_length(groups); i++) {
         autocomplete_add(certs_ac, groups[i]);
     }
     g_strfreev(groups);
@@ -117,8 +116,7 @@ tlscerts_list(void)
     gsize len = 0;
     gchar** groups = g_key_file_get_groups(tlscerts, &len);
 
-    int i = 0;
-    for (i = 0; i < g_strv_length(groups); i++) {
+    for (int i = 0; i < g_strv_length(groups); i++) {
         char* fingerprint = strdup(groups[i]);
         int version = g_key_file_get_integer(tlscerts, fingerprint, "version", NULL);
         char* serialnumber = g_key_file_get_string(tlscerts, fingerprint, "serialnumber", NULL);
@@ -209,8 +207,7 @@ tlscerts_new(const char* const fingerprint, int version, const char* const seria
     cert->subject_organisation_unit = NULL;
     cert->subject_email = NULL;
     gchar** fields = g_strsplit(subjectname, "/", 0);
-    int i = 0;
-    for (i = 0; i < g_strv_length(fields); i++) {
+    for (int i = 0; i < g_strv_length(fields); i++) {
         gchar** keyval = g_strsplit(fields[i], "=", 2);
         if (g_strv_length(keyval) == 2) {
             if ((g_strcmp0(keyval[0], "C") == 0) || (g_strcmp0(keyval[0], "countryName") == 0)) {
@@ -251,7 +248,7 @@ tlscerts_new(const char* const fingerprint, int version, const char* const seria
     cert->issuer_organisation_unit = NULL;
     cert->issuer_email = NULL;
     fields = g_strsplit(issuername, "/", 0);
-    for (i = 0; i < g_strv_length(fields); i++) {
+    for (int i = 0; i < g_strv_length(fields); i++) {
         gchar** keyval = g_strsplit(fields[i], "=", 2);
         if (g_strv_length(keyval) == 2) {
             if ((g_strcmp0(keyval[0], "C") == 0) || (g_strcmp0(keyval[0], "countryName") == 0)) {
diff --git a/src/log.c b/src/log.c
index 38971f26..541a263f 100644
--- a/src/log.c
+++ b/src/log.c
@@ -244,10 +244,9 @@ _rotate_log_file(void)
     gchar* log_file = g_strdup(mainlogfile);
     size_t len = strlen(log_file);
     gchar* log_file_new = malloc(len + 4);
-    int i = 1;
 
     // find an empty name. from .log -> log.01 -> log.99
-    for (; i < 100; i++) {
+    for (int i=1; i < 100; i++) {
         g_sprintf(log_file_new, "%s.%02d", log_file, i);
         if (!g_file_test(log_file_new, G_FILE_TEST_EXISTS))
             break;
@@ -780,7 +779,6 @@ log_stderr_handler(void)
     char* const buf = stderr_buf;
     ssize_t size;
     int retry = 0;
-    int i;
 
     if (!stderr_inited)
         return;
@@ -792,7 +790,7 @@ log_stderr_handler(void)
         if (size <= 0 || retry++ >= STDERR_RETRY_NR)
             break;
 
-        for (i = 0; i < size; ++i) {
+        for (int i = 0; i < size; ++i) {
             if (buf[i] == '\n') {
                 log_msg(stderr_level, "stderr", s->str);
                 g_string_assign(s, "");
diff --git a/src/omemo/crypto.c b/src/omemo/crypto.c
index 316f6f63..380551ad 100644
--- a/src/omemo/crypto.c
+++ b/src/omemo/crypto.c
@@ -287,8 +287,7 @@ omemo_decrypt_func(signal_buffer** output, int cipher, const uint8_t* key, size_
         assert(FALSE);
     }
 
-    int i;
-    for (i = 0; i < padding; i++) {
+    for (int i = 0; i < padding; i++) {
         if (plaintext[plaintext_len - 1 - i] != padding) {
             ret = SG_ERR_UNKNOWN;
             goto out;
diff --git a/src/pgp/gpg.c b/src/pgp/gpg.c
index 1c2d2aca..73b985fb 100644
--- a/src/pgp/gpg.c
+++ b/src/pgp/gpg.c
@@ -202,8 +202,7 @@ p_gpg_on_connect(const char* const barejid)
         return;
     }
 
-    int i = 0;
-    for (i = 0; i < len; i++) {
+    for (int i = 0; i < len; i++) {
         GError* gerr = NULL;
         gchar* jid = jids[i];
         gchar* keyid = g_key_file_get_string(pubkeyfile, jid, "keyid", &gerr);
@@ -777,9 +776,8 @@ p_gpg_format_fp_str(char* fp)
     }
 
     GString* format = g_string_new("");
-    int i;
     int len = strlen(fp);
-    for (i = 0; i < len; i++) {
+    for (int i = 0; i < len; i++) {
         g_string_append_c(format, fp[i]);
         if (((i + 1) % 4 == 0) && (i + 1 < len)) {
             g_string_append_c(format, ' ');
diff --git a/src/plugins/api.c b/src/plugins/api.c
index cbf30dd1..26d78a6e 100644
--- a/src/plugins/api.c
+++ b/src/plugins/api.c
@@ -123,7 +123,7 @@ api_register_command(const char* const plugin_name, const char* command_name, in
 
     help->tags[0] = NULL;
 
-    int i = 0;
+    int i;
     for (i = 0; synopsis[i] != NULL; i++) {
         help->synopsis[i] = strdup(synopsis[i]);
     }
diff --git a/src/plugins/plugins.c b/src/plugins/plugins.c
index a225c78a..580f98f0 100644
--- a/src/plugins/plugins.c
+++ b/src/plugins/plugins.c
@@ -84,8 +84,7 @@ plugins_init(void)
     // load plugins
     gchar** plugins_pref = prefs_get_plugins();
     if (plugins_pref) {
-        int i;
-        for (i = 0; i < g_strv_length(plugins_pref); i++) {
+        for (int i = 0; i < g_strv_length(plugins_pref); i++) {
             gboolean loaded = FALSE;
             gchar* filename = plugins_pref[i];
 #ifdef HAVE_PYTHON
diff --git a/src/tools/autocomplete.c b/src/tools/autocomplete.c
index a3763bfb..bd766e52 100644
--- a/src/tools/autocomplete.c
+++ b/src/tools/autocomplete.c
@@ -171,8 +171,7 @@ autocomplete_add(Autocomplete ac, const char* item)
 void
 autocomplete_add_all(Autocomplete ac, char** items)
 {
-    int i = 0;
-    for (i = 0; i < g_strv_length(items); i++) {
+    for (int i = 0; i < g_strv_length(items); i++) {
         autocomplete_add(ac, items[i]);
     }
 }
@@ -202,8 +201,7 @@ autocomplete_remove(Autocomplete ac, const char* const item)
 void
 autocomplete_remove_all(Autocomplete ac, char** items)
 {
-    int i = 0;
-    for (i = 0; i < g_strv_length(items); i++) {
+    for (int i = 0; i < g_strv_length(items); i++) {
         autocomplete_remove(ac, items[i]);
     }
 }
@@ -310,10 +308,9 @@ autocomplete_param_with_func(const char* const input, char* command, autocomplet
     int len = strlen(command_cpy);
 
     if (strncmp(input, command_cpy, len) == 0) {
-        int i;
         int inp_len = strlen(input);
         char prefix[inp_len];
-        for (i = len; i < inp_len; i++) {
+        for (int i = len; i < inp_len; i++) {
             prefix[i - len] = input[i];
         }
         prefix[inp_len - len] = '\0';
@@ -341,9 +338,8 @@ autocomplete_param_with_ac(const char* const input, char* command, Autocomplete
     int len = strlen(command_cpy);
     int inp_len = strlen(input);
     if (strncmp(input, command_cpy, len) == 0) {
-        int i;
         char prefix[inp_len];
-        for (i = len; i < inp_len; i++) {
+        for (int i = len; i < inp_len; i++) {
             prefix[i - len] = input[i];
         }
         prefix[inp_len - len] = '\0';
diff --git a/src/tools/parser.c b/src/tools/parser.c
index 364dd436..c251c13a 100644
--- a/src/tools/parser.c
+++ b/src/tools/parser.c
@@ -62,8 +62,7 @@ _parse_args_helper(const char* const inp, int min, int max, gboolean* result, gb
     GSList* tokens = NULL;
 
     // add tokens to GSList
-    int i;
-    for (i = 0; i < inp_size; i++) {
+    for (int i = 0; i < inp_size; i++) {
         gchar* curr_ch = g_utf8_offset_to_pointer(copy, i);
         gunichar curr_uni = g_utf8_get_char(curr_ch);
 
@@ -255,12 +254,11 @@ count_tokens(const char* const string)
     int length = g_utf8_strlen(string, -1);
     gboolean in_quotes = FALSE;
     int num_tokens = 0;
-    int i = 0;
 
     // include first token
     num_tokens++;
 
-    for (i = 0; i < length; i++) {
+    for (int i = 0; i < length; i++) {
         gchar* curr_ch = g_utf8_offset_to_pointer(string, i);
         gunichar curr_uni = g_utf8_get_char(curr_ch);
 
@@ -288,12 +286,11 @@ get_start(const char* const string, int tokens)
     gboolean in_quotes = FALSE;
     char* result_str = NULL;
     int num_tokens = 0;
-    int i = 0;
 
     // include first token
     num_tokens++;
 
-    for (i = 0; i < length; i++) {
+    for (int i = 0; i < length; i++) {
         gchar* curr_ch = g_utf8_offset_to_pointer(string, i);
         gunichar curr_uni = g_utf8_get_char(curr_ch);
 
@@ -327,8 +324,7 @@ GHashTable*
 parse_options(gchar** args, gchar** opt_keys, gboolean* res)
 {
     GList* keys = NULL;
-    int i;
-    for (i = 0; i < g_strv_length(opt_keys); i++) {
+    for (int i = 0; i < g_strv_length(opt_keys); i++) {
         keys = g_list_append(keys, opt_keys[i]);
     }
 
@@ -343,9 +339,8 @@ parse_options(gchar** args, gchar** opt_keys, gboolean* res)
     }
 
     // validate options
-    int curr;
     GList* found_keys = NULL;
-    for (curr = 0; curr < g_strv_length(args); curr += 2) {
+    for (int curr = 0; curr < g_strv_length(args); curr += 2) {
         // check if option valid
         if (g_list_find_custom(keys, args[curr], (GCompareFunc)g_strcmp0) == NULL) {
             *res = FALSE;
@@ -378,7 +373,7 @@ parse_options(gchar** args, gchar** opt_keys, gboolean* res)
     // create map
     options = g_hash_table_new(g_str_hash, g_str_equal);
     *res = TRUE;
-    for (curr = 0; curr < g_strv_length(args); curr += 2) {
+    for (int curr = 0; curr < g_strv_length(args); curr += 2) {
         g_hash_table_insert(options, args[curr], args[curr + 1]);
     }
 
diff --git a/src/ui/console.c b/src/ui/console.c
index a3797963..cb2bb888 100644
--- a/src/ui/console.c
+++ b/src/ui/console.c
@@ -859,8 +859,7 @@ cons_show_account_list(gchar** accounts)
     int size = g_strv_length(accounts);
     if (size > 0) {
         cons_show("Accounts:");
-        int i = 0;
-        for (i = 0; i < size; i++) {
+        for (int i = 0; i < size; i++) {
             if ((connection_get_status() == JABBER_CONNECTED) && (g_strcmp0(session_get_account_name(), accounts[i]) == 0)) {
                 resource_presence_t presence = accounts_get_last_presence(accounts[i]);
                 theme_item_t presence_colour = theme_main_presence_attrs(string_from_resource_presence(presence));
@@ -2718,13 +2717,12 @@ cons_show_bookmarks_ignore(gchar** list, gsize len)
         return;
     }
 
-    int i;
     ProfWin* console = wins_get_console();
 
     cons_show("");
     cons_show("Ignored bookmarks:");
 
-    for (i = 0; i < len; i++) {
+    for (int i = 0; i < len; i++) {
         win_print(console, THEME_DEFAULT, "-", "  %s", list[i]);
         win_newline(console);
     }
diff --git a/src/ui/core.c b/src/ui/core.c
index 4bbb23de..aad6d387 100644
--- a/src/ui/core.c
+++ b/src/ui/core.c
@@ -1222,8 +1222,7 @@ void
 ui_show_lines(ProfWin* window, gchar** lines)
 {
     if (lines) {
-        int i;
-        for (i = 0; lines[i] != NULL; i++) {
+        for (int i = 0; lines[i] != NULL; i++) {
             win_println(window, THEME_DEFAULT, "-", "%s", lines[i]);
         }
     }
diff --git a/src/ui/statusbar.c b/src/ui/statusbar.c
index 3dfdf086..9997755b 100644
--- a/src/ui/statusbar.c
+++ b/src/ui/statusbar.c
@@ -296,8 +296,7 @@ status_bar_draw(void)
         pos = 0;
     }
     gint max_tabs = prefs_get_statusbartabs();
-    int i = 1;
-    for (i = 1; i <= max_tabs; i++) {
+    for (int i = 1; i <= max_tabs; i++) {
         StatusBarTab* tab = g_hash_table_lookup(statusbar->tabs, GINT_TO_POINTER(i));
         if (tab) {
             pos = _status_bar_draw_tab(tab, pos, i);
@@ -319,8 +318,7 @@ _extended_new(void)
         return FALSE;
     }
 
-    int i = 0;
-    for (i = max_tabs + 1; i <= tabs_count; i++) {
+    for (int i = max_tabs + 1; i <= tabs_count; i++) {
         StatusBarTab* tab = g_hash_table_lookup(statusbar->tabs, GINT_TO_POINTER(i));
         if (tab && tab->highlight) {
             return TRUE;
@@ -527,8 +525,7 @@ _tabs_width(void)
 
     if (show_name && show_number) {
         int width = g_hash_table_size(statusbar->tabs) > max_tabs ? 4 : 1;
-        int i = 0;
-        for (i = 1; i <= max_tabs; i++) {
+        for (int i = 1; i <= max_tabs; i++) {
             StatusBarTab* tab = g_hash_table_lookup(statusbar->tabs, GINT_TO_POINTER(i));
             if (tab) {
                 gboolean is_current = i == statusbar->current_tab;
@@ -547,8 +544,7 @@ _tabs_width(void)
 
     if (show_name && !show_number) {
         int width = g_hash_table_size(statusbar->tabs) > max_tabs ? 4 : 1;
-        int i = 0;
-        for (i = 1; i <= max_tabs; i++) {
+        for (int i = 1; i <= max_tabs; i++) {
             StatusBarTab* tab = g_hash_table_lookup(statusbar->tabs, GINT_TO_POINTER(i));
             if (tab) {
                 gboolean is_current = i == statusbar->current_tab;
diff --git a/src/ui/titlebar.c b/src/ui/titlebar.c
index e587bab0..a22abaeb 100644
--- a/src/ui/titlebar.c
+++ b/src/ui/titlebar.c
@@ -190,8 +190,7 @@ _title_bar_draw(void)
 
     werase(win);
     wmove(win, 0, 0);
-    int i;
-    for (i = 0; i < 45; i++) {
+    for (int i = 0; i < 45; i++) {
         waddch(win, ' ');
     }
 
diff --git a/src/ui/window.c b/src/ui/window.c
index 5a1a90dc..687af3b2 100644
--- a/src/ui/window.c
+++ b/src/ui/window.c
@@ -1613,8 +1613,7 @@ _win_print_internal(ProfWin* window, const char* show_char, int pad_indent, GDat
 static void
 _win_indent(WINDOW* win, int size)
 {
-    int i = 0;
-    for (i = 0; i < size; i++) {
+    for (int i = 0; i < size; i++) {
         waddch(win, ' ');
     }
 }
@@ -1743,8 +1742,7 @@ win_print_trackbar(ProfWin* window)
     wbkgdset(window->layout->win, theme_attrs(THEME_TRACKBAR));
     wattron(window->layout->win, theme_attrs(THEME_TRACKBAR));
 
-    int i;
-    for (i = 1; i < cols; i++) {
+    for (int i = 1; i < cols; i++) {
         wprintw(window->layout->win, "-");
     }
 
@@ -1756,11 +1754,11 @@ win_print_trackbar(ProfWin* window)
 void
 win_redraw(ProfWin* window)
 {
-    int i, size;
+    int size;
     werase(window->layout->win);
     size = buffer_size(window->layout->buffer);
 
-    for (i = 0; i < size; i++) {
+    for (int i = 0; i < size; i++) {
         ProfBuffEntry* e = buffer_get_entry(window->layout->buffer, i);
 
         if (e->display_from == NULL && e->message && e->message[0] == '-') {
@@ -1935,12 +1933,12 @@ win_handle_command_exec_result_note(ProfWin* window, const char* const type, con
 void
 win_insert_last_read_position_marker(ProfWin* window, char* id)
 {
-    int i, size;
+    int size;
     size = buffer_size(window->layout->buffer);
 
     // TODO: this is somewhat costly. We should improve this later.
     // check if we already have a separator present
-    for (i = 0; i < size; i++) {
+    for (int i = 0; i < size; i++) {
         ProfBuffEntry* e = buffer_get_entry(window->layout->buffer, i);
 
         // if yes, don't print a new one
diff --git a/src/xmpp/capabilities.c b/src/xmpp/capabilities.c
index f3788a41..98a5c399 100644
--- a/src/xmpp/capabilities.c
+++ b/src/xmpp/capabilities.c
@@ -387,8 +387,7 @@ _caps_by_ver(const char* const ver)
     gchar** features_list = g_key_file_get_string_list(cache, ver, "features", &features_len, NULL);
     GSList* features = NULL;
     if (features_list && features_len > 0) {
-        int i;
-        for (i = 0; i < features_len; i++) {
+        for (int i = 0; i < features_len; i++) {
             features = g_slist_append(features, features_list[i]);
         }
     }
diff --git a/src/xmpp/stanza.c b/src/xmpp/stanza.c
index 48c09953..fbbbfc9c 100644
--- a/src/xmpp/stanza.c
+++ b/src/xmpp/stanza.c
@@ -237,8 +237,7 @@ stanza_create_http_upload_request(xmpp_ctx_t* ctx, const char* const id,
     xmpp_stanza_t* filename_txt = xmpp_stanza_new(ctx);
     char* filename_cpy = strdup(upload->filename);
     // strip spaces from filename (servers don't spaces)
-    int i;
-    for (i = 0; i < strlen(filename_cpy); i++) {
+    for (int i = 0; i < strlen(filename_cpy); i++) {
         if (filename_cpy[i] == ' ') {
             filename_cpy[i] = '_';
         }
@@ -1826,8 +1825,7 @@ stanza_create_caps_from_query_element(xmpp_stanza_t* query)
         xmpp_stanza_t* id_stanza = curr_identity->data;
         const char* stanza_lang = xmpp_stanza_get_attribute(id_stanza, "xml:lang");
         if (stanza_lang) {
-            int i = 0;
-            for (i = 0; i < num_langs; i++) {
+            for (int i = 0; i < num_langs; i++) {
                 if (g_strcmp0(langs[i], stanza_lang) == 0) {
                     found = id_stanza;
                     break;
@@ -1929,8 +1927,7 @@ stanza_get_error_message(xmpp_stanza_t* stanza)
             STANZA_NAME_UNEXPECTED_REQUEST
         };
 
-        int i;
-        for (i = 0; i < ARRAY_SIZE(defined_conditions); i++) {
+        for (int i = 0; i < ARRAY_SIZE(defined_conditions); i++) {
             xmpp_stanza_t* cond_stanza = xmpp_stanza_get_child_by_name(error_stanza, defined_conditions[i]);
             if (cond_stanza) {
                 char* result = strdup(xmpp_stanza_get_name(cond_stanza));
@@ -2334,8 +2331,7 @@ stanza_create_omemo_devicelist_publish(xmpp_ctx_t* ctx, GList* const ids)
     xmpp_stanza_set_name(list, "list");
     xmpp_stanza_set_ns(list, "eu.siacs.conversations.axolotl");
 
-    GList* i;
-    for (i = ids; i != NULL; i = i->next) {
+    for (GList *i = ids; i != NULL; i = i->next) {
         xmpp_stanza_t* device = xmpp_stanza_new(ctx);
         xmpp_stanza_set_name(device, "device");
         char* id = g_strdup_printf("%d", GPOINTER_TO_INT(i->data));