diff --git a/src/bfu/inphist.c b/src/bfu/inphist.c
index 5e4ab6d6e..969b04fab 100644
--- a/src/bfu/inphist.c
+++ b/src/bfu/inphist.c
@@ -284,9 +284,9 @@ add_to_input_history(struct input_history *history, char *data,
 
 /* Load history file */
 int
-load_input_history(struct input_history *history, char *filename)
+load_input_history(struct input_history *history, const char *filename)
 {
-	char *history_file = filename;
+	char *history_file = (char *)filename;
 	char line[MAX_STR_LEN];
 	FILE *file;
 
@@ -319,7 +319,7 @@ load_input_history(struct input_history *history, char *filename)
 /* Write history list to file. It returns a value different from 0 in case of
  * failure, 0 on success. */
 int
-save_input_history(struct input_history *history, char *filename)
+save_input_history(struct input_history *history, const char *filename)
 {
 	struct input_history_entry *entry;
 	struct secure_save_info *ssi;
diff --git a/src/bfu/inphist.h b/src/bfu/inphist.h
index 2f71e84eb..a51962e90 100644
--- a/src/bfu/inphist.h
+++ b/src/bfu/inphist.h
@@ -54,11 +54,11 @@ void do_tab_compl_unambiguous(struct dialog_data *,
 			      LIST_OF(struct input_history_entry) *);
 
 /* Load history file from elinks home. */
-int load_input_history(struct input_history *history, char *filename);
+int load_input_history(struct input_history *history, const char *filename);
 
 /* Write history list to @filebane in elinks home. It returns a value different
  * from 0 in case of failure, 0 on success. */
-int save_input_history(struct input_history *history, char *filename);
+int save_input_history(struct input_history *history, const char *filename);
 
 void dlg_set_history(struct widget_data *);
 
diff --git a/src/viewer/text/search.c b/src/viewer/text/search.c
index c97bcbc2f..c0f7a0d2f 100644
--- a/src/viewer/text/search.c
+++ b/src/viewer/text/search.c
@@ -987,7 +987,7 @@ get_searched_all(struct session *ses, struct document_view *doc_view, struct poi
 }
 
 static enum find_error
-search_for_do(struct session *ses, char *str, int direction,
+search_for_do(struct session *ses, const char *str, int direction,
 	      int report_errors)
 {
 	struct document_view *doc_view;
@@ -1031,7 +1031,7 @@ search_for_do(struct session *ses, char *str, int direction,
 }
 
 static void
-search_for_back(struct session *ses, char *str)
+search_for_back(struct session *ses, const char *str)
 {
 	assert(ses && str);
 	if_assert_failed return;
@@ -1040,7 +1040,7 @@ search_for_back(struct session *ses, char *str)
 }
 
 void
-search_for(struct session *ses, char *str)
+search_for(struct session *ses, const char *str)
 {
 	assert(ses && str);
 	if_assert_failed return;
diff --git a/src/viewer/text/search.h b/src/viewer/text/search.h
index b0c932971..e9a14e4e0 100644
--- a/src/viewer/text/search.h
+++ b/src/viewer/text/search.h
@@ -22,7 +22,7 @@ enum frame_event_status find_next(struct session *ses, struct document_view *doc
 enum frame_event_status move_search_next(struct session *ses, struct document_view *doc_view);
 enum frame_event_status move_search_prev(struct session *ses, struct document_view *doc_view);
 
-void search_for(struct session *ses, char *str);
+void search_for(struct session *ses, const char *str);
 enum frame_event_status search_dlg(struct session *ses, struct document_view *doc_view, int direction);
 enum frame_event_status search_typeahead(struct session *ses, struct document_view *doc_view, action_id_T action_id);