diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index c40cf4b0..daae84d0 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -12,7 +12,7 @@ jobs:
 
     strategy:
       matrix:
-        flavor: [debian, fedora]
+        flavor: [debian, fedora, tumbleweed, ubuntu]
 
     name: Linux
     steps:
@@ -22,15 +22,15 @@ jobs:
           docker build -f Dockerfile.${{ matrix.flavor }} -t profanity .
           docker run profanity ./ci-build.sh
 
-# macos:
-#   runs-on: macos-latest
-#   name: macOS
-#   steps:
-#     - uses: actions/checkout@v2
-#     - name: Run brew bundle
-#       run: brew bundle
-#     - name: Run tests
-#       env:
-#         # Ensure that "keg-only" Homebrew versions are used.
-#         PKG_CONFIG_PATH: "/usr/local/opt/ncurses/lib/pkgconfig:/usr/local/opt/expat/lib/pkgconfig:/usr/local/opt/curl/lib/pkgconfig:/usr/local/opt/openssl/lib/pkgconfig:/usr/local/opt/libffi/lib/pkgconfig:/usr/local/opt/sqlite/lib/pkgconfig:$PKG_CONFIG_PATH"
-#       run: ./ci-build.sh
+  macos:
+    runs-on: macos-latest
+    name: macOS
+    steps:
+      - uses: actions/checkout@v2
+      - name: Run brew bundle
+        run: brew bundle
+      - name: Run tests
+        env:
+          # Ensure that "keg-only" Homebrew versions are used.
+          PKG_CONFIG_PATH: "/usr/local/opt/ncurses/lib/pkgconfig:/usr/local/opt/expat/lib/pkgconfig:/usr/local/opt/curl/lib/pkgconfig:/usr/local/opt/openssl/lib/pkgconfig:/usr/local/opt/libffi/lib/pkgconfig:/usr/local/opt/sqlite/lib/pkgconfig:$PKG_CONFIG_PATH"
+        run: ./ci-build.sh
diff --git a/Dockerfile.arch b/Dockerfile.arch
index a3644b9f..1cd4cd03 100644
--- a/Dockerfile.arch
+++ b/Dockerfile.arch
@@ -1,4 +1,4 @@
-FROM archlinux/base
+FROM archlinux/latest
 
 RUN pacman -Syu --noconfirm && pacman -S --needed --noconfirm \
   autoconf \
diff --git a/Dockerfile.ubuntu b/Dockerfile.ubuntu
index 840cd736..9686084f 100644
--- a/Dockerfile.ubuntu
+++ b/Dockerfile.ubuntu
@@ -26,7 +26,8 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   libxss-dev \
   make \
   pkg-config \
-  python-dev \
+  python3-dev \
+  python-dev-is-python3 \
   libsqlite3-dev
 
 RUN mkdir -p /usr/src/{stabber,libstrophe,profanity}
diff --git a/configure.ac b/configure.ac
index 566c3c80..4a6a8ba2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -210,12 +210,21 @@ AS_IF([test "x$enable_icons_and_clipboard" != xno],
                                   [AC_MSG_NOTICE([gtk+-3.0/gtk+2.0 not found, icons and clipboard not enabled])])])])])
 
 AS_IF([test "x$PLATFORM" = xosx],
-    [AC_CHECK_FILE([/usr/local/opt/readline/lib],
+        [AC_PATH_PROG([BREW], [brew], ["failed"],
+            [$PATH:/opt/homebrew/bin:/usr/local/bin])
+        AS_IF([test "x$BREW" = xfailed],
+            [AC_CHECK_FILE([/opt/local/lib/libreadline.dylib],
+                [READLINE_PREFIX="/opt/local"],
+                [READLINE_PREFIX="/usr/local"])],
+            [READLINE_PREFIX="`$BREW --prefix readline`"])])
+
+AS_IF([test "x$PLATFORM" = xosx],
+    [AC_CHECK_FILE([$READLINE_PREFIX/lib/libreadline.dylib],
         [LIBS="-lreadline $LIBS"
-            AM_CPPFLAGS="-I/usr/local/opt/readline/include $AM_CPPFLAGS"
-            AM_LDFLAGS="-L/usr/local/opt/readline/lib $AM_LDFLAGS"
+            AM_CPPFLAGS="-I$READLINE_PREFIX/include $AM_CPPFLAGS"
+            AM_LDFLAGS="-L$READLINE_PREFIX/lib $AM_LDFLAGS"
             AC_SUBST(AM_LDFLAGS)],
-        [AC_MSG_ERROR([libreadline is required for profanity])])],
+        [AC_MSG_ERROR([libreadline is required for profanity. Install it with Homebrew, MacPorts, or manually into /usr/local])])],
 
       [test "x$PLATFORM" = xopenbsd],
       [AC_CHECK_FILE([/usr/local/include/ereadline],
diff --git a/src/omemo/omemo.c b/src/omemo/omemo.c
index e1126e62..4d53ad0c 100644
--- a/src/omemo/omemo.c
+++ b/src/omemo/omemo.c
@@ -84,6 +84,7 @@ static unsigned char* _omemo_fingerprint_decode(const char* const fingerprint, s
 static char* _omemo_unformat_fingerprint(const char* const fingerprint_formatted);
 static void _cache_device_identity(const char* const jid, uint32_t device_id, ec_public_key* identity);
 static void _g_hash_table_free(GHashTable* hash_table);
+static void _acquire_sender_devices_list(void);
 
 typedef gboolean (*OmemoDeviceListHandler)(const char* const jid, GList* device_list);
 
@@ -384,21 +385,26 @@ omemo_publish_crypto_materials(void)
         return;
     }
 
+    omemo_bundle_publish(true);
+}
+
+static void _acquire_sender_devices_list(void) {
     char* barejid = connection_get_barejid();
 
-    /* Ensure we get our current device list, and it gets updated with our
-     * device_id */
     g_hash_table_insert(omemo_ctx.device_list_handler, strdup(barejid), _handle_own_device_list);
     omemo_devicelist_request(barejid);
 
-    omemo_bundle_publish(true);
-
     free(barejid);
 }
 
 void
 omemo_start_sessions(void)
 {
+    // before any session may be started, a list on
+    // available sender devices must be acquired
+    log_debug("[OMEMO] Acquiring sender devices list");
+    _acquire_sender_devices_list();
+
     GSList* contacts = roster_get_contacts(ROSTER_ORD_NAME);
     if (contacts) {
         GSList* curr;
diff --git a/src/plugins/callbacks.c b/src/plugins/callbacks.c
index 92c0a9f4..4a73f15b 100644
--- a/src/plugins/callbacks.c
+++ b/src/plugins/callbacks.c
@@ -82,7 +82,7 @@ _free_command_help(CommandHelp* help)
     free(help->desc);
 
     i = 0;
-    while (help->args[i] != NULL && help->args[i][0] != NULL) {
+    while (help->args[i][0] != NULL) {
         free(help->args[i][0]);
         free(help->args[i][1]);
         i++;
diff --git a/src/plugins/python_api.c b/src/plugins/python_api.c
index 8ea54514..90e33579 100644
--- a/src/plugins/python_api.c
+++ b/src/plugins/python_api.c
@@ -158,7 +158,7 @@ python_api_register_command(PyObject* self, PyObject* args)
         c_synopsis[len] = NULL;
 
         Py_ssize_t args_len = PyList_Size(arguments);
-        char* c_arguments[args_len == 0 ? 0 : args_len + 1][2];
+        char* c_arguments[args_len + 1][2];
         for (i = 0; i < args_len; i++) {
             PyObject* item = PyList_GetItem(arguments, i);
             Py_ssize_t len2 = PyList_Size(item);
@@ -196,7 +196,7 @@ python_api_register_command(PyObject* self, PyObject* args)
             free(c_synopsis[i++]);
         }
         i = 0;
-        while (c_arguments[i] != NULL && c_arguments[i][0] != NULL) {
+        while (c_arguments[i][0] != NULL) {
             free(c_arguments[i][0]);
             free(c_arguments[i][1]);
             i++;
diff --git a/src/xmpp/message.c b/src/xmpp/message.c
index ab4d48c6..70371576 100644
--- a/src/xmpp/message.c
+++ b/src/xmpp/message.c
@@ -231,7 +231,13 @@ _message_handler(xmpp_conn_t* const conn, xmpp_stanza_t* const stanza, void* con
         gboolean is_carbon = FALSE;
 
         // XEP-0280: Message Carbons
-        xmpp_stanza_t* carbons = xmpp_stanza_get_child_by_ns(stanza, STANZA_NS_CARBONS);
+        // Only allow `<sent xmlns='urn:xmpp:carbons:2'>` and `<received xmlns='urn:xmpp:carbons:2'>` carbons
+        // Thus ignoring `<private xmlns="urn:xmpp:carbons:2"/>`
+        xmpp_stanza_t* carbons = xmpp_stanza_get_child_by_name_and_ns(stanza, STANZA_NAME_SENT, STANZA_NS_CARBONS);
+        if (!carbons) {
+            carbons = xmpp_stanza_get_child_by_name_and_ns(stanza, STANZA_NAME_RECEIVED, STANZA_NS_CARBONS);
+        }
+
         if (carbons) {
 
             // carbon must come from ourselves
@@ -1291,7 +1297,7 @@ _handle_carbons(xmpp_stanza_t* const stanza)
     }
     */
 
-    if ((g_strcmp0(name, "received") != 0) && (g_strcmp0(name, "sent") != 0)) {
+    if ((g_strcmp0(name, STANZA_NAME_RECEIVED) != 0) && (g_strcmp0(name, STANZA_NAME_SENT) != 0)) {
         log_warning("Carbon received with unrecognised stanza name: %s", name);
         return NULL;
     }
diff --git a/src/xmpp/stanza.h b/src/xmpp/stanza.h
index b4c65641..9e957749 100644
--- a/src/xmpp/stanza.h
+++ b/src/xmpp/stanza.h
@@ -119,6 +119,8 @@
 #define STANZA_NAME_REPORT           "report"
 #define STANZA_NAME_EVENT            "event"
 #define STANZA_NAME_MOOD             "mood"
+#define STANZA_NAME_RECEIVED         "received"
+#define STANZA_NAME_SENT             "sent"
 
 // error conditions
 #define STANZA_NAME_BAD_REQUEST             "bad-request"