diff --git a/check-cwe134.sh b/check-cwe134.sh
index 4ff6b67f..c86f475a 100755
--- a/check-cwe134.sh
+++ b/check-cwe134.sh
@@ -4,6 +4,14 @@
 # This script detects potentially unsafe usage of format string functions
 # where user-controlled data may be passed without "%s" wrapper.
 #
+# Checks performed:
+#   1. Direct variable passed as format string: cons_show(var);
+#   2. Variable passed as format arg through multi-arg wrappers:
+#      win_println(win, theme, ch, var);  (no format specifiers in var position)
+#   3. GString->str passed as format argument without "%s"
+#   4. Presence of __attribute__((format)) on printf-like wrapper declarations
+#   5. Format string mismatch: more arguments than format specifiers
+#
 # Usage: ./check-cwe134.sh [directory]
 
 set -e
@@ -14,38 +22,145 @@ echo "=== CWE-134 Format String Vulnerability Check ==="
 echo "Scanning: $DIR"
 echo ""
 
-# Functions that accept format strings
-FORMAT_FUNCS="cons_show|cons_debug|cons_show_error|log_info|log_error|log_warning|log_debug|win_println|win_print"
+# Functions that accept format strings (direct: first arg is format)
+DIRECT_FORMAT_FUNCS="cons_show|cons_debug|cons_show_error|log_info|log_error|log_warning|log_debug"
+
+# Functions where format string is not the first arg (multi-arg wrappers)
+# win_print(win, theme, char, FORMAT, ...)
+# win_println(win, theme, char, FORMAT, ...)
+# win_println_indent(win, pad, FORMAT, ...)
+# win_append(win, theme, FORMAT, ...)
+# win_appendln(win, theme, FORMAT, ...)
+# win_append_highlight(win, theme, FORMAT, ...)
+# win_appendln_highlight(win, theme, FORMAT, ...)
+# win_command_exec_error(win, cmd, FORMAT, ...)
+MULTI_ARG_FORMAT_FUNCS="win_print|win_println|win_println_indent|win_append|win_appendln|win_append_highlight|win_appendln_highlight|win_command_exec_error"
+
+ALL_FORMAT_FUNCS="$DIRECT_FORMAT_FUNCS|$MULTI_ARG_FORMAT_FUNCS"
 
 ERRORS=0
 
-echo "Checking for unsafe format string usage..."
+# ---------------------------------------------------------------------------
+# Check 1: Direct format functions called with single variable (no format string)
+# ---------------------------------------------------------------------------
+echo "Check 1: Direct variable as format string..."
 echo ""
 
-# Pattern 1: function call with single variable argument (no format string)
-# Example: cons_show(variable);  - BAD
-# Example: cons_show("%s", variable);  - OK
-# Matches: func(identifier) or func(identifier->member) or func(identifier[index])
-RESULTS=$(grep -rn --include="*.c" -P "($FORMAT_FUNCS)\s*\(\s*[a-zA-Z_][a-zA-Z0-9_]*(\s*->\s*\w+|\s*\[\s*\w+\s*\])?\s*\)\s*;" "$DIR" 2>/dev/null || true)
+# Pattern: func(identifier) or func(identifier->member) or func(identifier[index])
+RESULTS=$(grep -rn --include="*.c" -P "($DIRECT_FORMAT_FUNCS)\s*\(\s*[a-zA-Z_][a-zA-Z0-9_]*(\s*->\s*\w+|\s*\[\s*\w+\s*\])?\s*\)\s*;" "$DIR" 2>/dev/null || true)
 
 # Filter out function definitions, declarations, and safe api_* wrappers
 RESULTS=$(echo "$RESULTS" | grep -v "const char\|void \|^[^:]*:[0-9]*:[a-z_]*(\|api_cons_show\|api_log_" || true)
 
 if [ -n "$RESULTS" ]; then
-    echo "❌ POTENTIAL CWE-134 VULNERABILITIES FOUND:"
+    echo "❌ POTENTIAL CWE-134 VULNERABILITIES FOUND (direct format):"
     echo ""
     echo "$RESULTS"
     echo ""
-    ERRORS=$(echo "$RESULTS" | wc -l)
+    ERRORS=$((ERRORS + $(echo "$RESULTS" | wc -l)))
 else
-    echo "✅ No obvious CWE-134 issues found."
+    echo "✅ No direct format string issues found."
 fi
 
-# Additional check: GString->str passed directly (not as %s argument)
+# ---------------------------------------------------------------------------
+# Check 2: Multi-arg wrappers where format position has a variable (not a string literal)
+# ---------------------------------------------------------------------------
+echo ""
+echo "Check 2: Multi-arg wrappers with variable as format argument..."
 echo ""
-echo "Checking for GString->str passed to format functions..."
 
-GSTRING_RESULTS=$(grep -rn --include="*.c" -P "($FORMAT_FUNCS)\s*\([^)]*->str\s*\)" "$DIR" 2>/dev/null | grep -v '"%s"' || true)
+# For win_print(win, theme, char, FORMAT, ...) and win_println(win, theme, char, FORMAT, ...):
+# FORMAT is the 4th argument
+MULTI4_RESULTS=$(grep -rn --include="*.c" -P "(win_print|win_println)\s*\(" "$DIR" 2>/dev/null | \
+    grep -v "win_println_indent\|win_println_va" | \
+    perl -ne '
+        if (/((win_print|win_println)\s*\()/) {
+            my $line = $_;
+            my $call_start = index($line, $1) + length($1);
+            my $rest = substr($line, $call_start);
+            my $depth = 0; my $commas = 0; my $i = 0;
+            for ($i = 0; $i < length($rest) && $commas < 3; $i++) {
+                my $c = substr($rest, $i, 1);
+                if ($c eq "(") { $depth++; }
+                elsif ($c eq ")") { $depth--; last if $depth < 0; }
+                elsif ($c eq "," && $depth == 0) { $commas++; }
+            }
+            if ($commas == 3) {
+                my $fmt_arg = substr($rest, $i);
+                $fmt_arg =~ s/^\s+//;
+                if ($fmt_arg =~ /^[a-zA-Z_]/) { print $line; }
+            }
+        }
+    ' || true)
+MULTI4_RESULTS=$(echo "$MULTI4_RESULTS" | grep -v "^$\|const char.*message\|void " || true)
+
+# For win_command_exec_error(win, cmd, FORMAT, ...):
+# FORMAT is the 3rd argument
+MULTI_CMD_RESULTS=$(grep -rn --include="*.c" -P "win_command_exec_error\s*\(" "$DIR" 2>/dev/null | \
+    perl -ne '
+        if (/(win_command_exec_error\s*\()/) {
+            my $line = $_;
+            my $call_start = index($line, $1) + length($1);
+            my $rest = substr($line, $call_start);
+            my $depth = 0; my $commas = 0; my $i = 0;
+            for ($i = 0; $i < length($rest) && $commas < 2; $i++) {
+                my $c = substr($rest, $i, 1);
+                if ($c eq "(") { $depth++; }
+                elsif ($c eq ")") { $depth--; last if $depth < 0; }
+                elsif ($c eq "," && $depth == 0) { $commas++; }
+            }
+            if ($commas == 2) {
+                my $fmt_arg = substr($rest, $i);
+                $fmt_arg =~ s/^\s+//;
+                if ($fmt_arg =~ /^[a-zA-Z_]/) { print $line; }
+            }
+        }
+    ' || true)
+MULTI_CMD_RESULTS=$(echo "$MULTI_CMD_RESULTS" | grep -v "^$\|const char.*error\|void \|ProfWin\*.*const char\*.*const char\*.*\.\.\." || true)
+
+# For 3-arg format functions: win_println_indent(win, pad, FORMAT, ...)
+# win_append(win, theme, FORMAT, ...) etc.
+MULTI3_RESULTS=$(grep -rn --include="*.c" -P "(win_println_indent|win_append|win_appendln|win_append_highlight|win_appendln_highlight)\s*\([^,]+,[^,]+,\s*(?!\")\s*[a-zA-Z_][a-zA-Z0-9_]*(\s*->\s*\w+|\s*\[\s*[^\]]+\])?\s*\)\s*;" "$DIR" 2>/dev/null || true)
+MULTI3_RESULTS=$(echo "$MULTI3_RESULTS" | grep -v "^$\|const char.*message\|void " || true)
+
+MULTI_RESULTS=""
+if [ -n "$MULTI4_RESULTS" ]; then
+    MULTI_RESULTS="$MULTI4_RESULTS"
+fi
+if [ -n "$MULTI3_RESULTS" ]; then
+    if [ -n "$MULTI_RESULTS" ]; then
+        MULTI_RESULTS="$MULTI_RESULTS
+$MULTI3_RESULTS"
+    else
+        MULTI_RESULTS="$MULTI3_RESULTS"
+    fi
+fi
+if [ -n "$MULTI_CMD_RESULTS" ]; then
+    if [ -n "$MULTI_RESULTS" ]; then
+        MULTI_RESULTS="$MULTI_RESULTS
+$MULTI_CMD_RESULTS"
+    else
+        MULTI_RESULTS="$MULTI_CMD_RESULTS"
+    fi
+fi
+
+if [ -n "$MULTI_RESULTS" ]; then
+    echo "❌ POTENTIAL CWE-134 VULNERABILITIES FOUND (multi-arg wrappers):"
+    echo ""
+    echo "$MULTI_RESULTS"
+    echo ""
+    ERRORS=$((ERRORS + $(echo "$MULTI_RESULTS" | wc -l)))
+else
+    echo "✅ No multi-arg format string issues found."
+fi
+
+# ---------------------------------------------------------------------------
+# Check 3: GString->str passed directly as format argument
+# ---------------------------------------------------------------------------
+echo ""
+echo "Check 3: GString->str passed to format functions..."
+
+GSTRING_RESULTS=$(grep -rn --include="*.c" -P "($ALL_FORMAT_FUNCS)\s*\([^)]*->str\s*\)" "$DIR" 2>/dev/null | grep -v '"%s"' || true)
 
 if [ -n "$GSTRING_RESULTS" ]; then
     echo "⚠️  GString->str passed without \"%s\" (review manually):"
@@ -54,6 +169,57 @@ if [ -n "$GSTRING_RESULTS" ]; then
     echo ""
 fi
 
+# ---------------------------------------------------------------------------
+# Check 4: Verify __attribute__((format)) on printf-like wrappers
+# ---------------------------------------------------------------------------
+echo ""
+echo "Check 4: Verifying __attribute__((format)) annotations..."
+echo ""
+
+ATTR_ERRORS=0
+
+# Functions that MUST have format attributes (declared in headers)
+REQUIRED_ATTRIBUTED=(
+    "cons_show"
+    "cons_debug"
+    "cons_show_error"
+    "cons_show_padded"
+    "log_debug"
+    "log_info"
+    "log_warning"
+    "log_error"
+    "win_print"
+    "win_println"
+    "win_println_indent"
+    "win_println_va"
+    "win_append"
+    "win_appendln"
+    "win_append_highlight"
+    "win_appendln_highlight"
+    "win_command_exec_error"
+)
+
+for func in "${REQUIRED_ATTRIBUTED[@]}"; do
+    # Check if the function declaration in headers has a preceding format attribute
+    HAS_ATTR=$(grep -B1 --include="*.h" -rn "void ${func}\s*(" "$DIR" 2>/dev/null | grep -E -c "format\(printf|G_GNUC_PRINTF" || true)
+    if [ "$HAS_ATTR" -eq 0 ]; then
+        echo "❌ Missing __attribute__((format(printf, ...))) for: $func"
+        ATTR_ERRORS=$((ATTR_ERRORS + 1))
+    fi
+done
+
+if [ "$ATTR_ERRORS" -eq 0 ]; then
+    echo "✅ All printf-like wrappers have format attributes."
+else
+    echo ""
+    echo "⚠️  $ATTR_ERRORS function(s) missing format attributes."
+    echo "   Add __attribute__((format(printf, N, M))) before the declaration."
+    ERRORS=$((ERRORS + ATTR_ERRORS))
+fi
+
+# ---------------------------------------------------------------------------
+# Summary
+# ---------------------------------------------------------------------------
 echo ""
 echo "=== Summary ==="
 echo "Critical issues: $ERRORS"
@@ -63,6 +229,9 @@ if [ "$ERRORS" -gt 0 ]; then
     echo "Fix by adding \"%s\" format specifier:"
     echo "  BAD:  cons_show(variable);"
     echo "  GOOD: cons_show(\"%s\", variable);"
+    echo ""
+    echo "  BAD:  win_println(win, theme, ch, variable);"
+    echo "  GOOD: win_println(win, theme, ch, \"%s\", variable);"
     exit 1
 fi
 
diff --git a/configure.ac b/configure.ac
index c79774e0..98dd4ff7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -385,7 +385,7 @@ AC_CHECK_LIB([util], [forkpty], [AM_CONDITIONAL([HAVE_FORKPTY], [true]) FORKPTY_
 AC_SUBST([FORKPTY_LIB])
 
 ## Default parameters
-AM_CFLAGS="$AM_CFLAGS -Wall -Wno-deprecated-declarations -std=gnu99 -ggdb3"
+AM_CFLAGS="$AM_CFLAGS -Wall -Wformat -Wformat-nonliteral -Wno-format-zero-length -Wno-deprecated-declarations -std=gnu99 -ggdb3"
 AM_LDFLAGS="$AM_LDFLAGS -export-dynamic"
 
 AS_IF([test "x$enable_coverage" = xyes],
diff --git a/src/command/cmd_defs.c b/src/command/cmd_defs.c
index 124749d6..5003be66 100644
--- a/src/command/cmd_defs.c
+++ b/src/command/cmd_defs.c
@@ -3067,7 +3067,7 @@ command_docgen(void)
 
     fclose(toc_fragment);
     fclose(main_fragment);
-    printf("\nProcessed %d commands.\n\n", g_list_length(cmds));
+    printf("\nProcessed %u commands.\n\n", g_list_length(cmds));
     g_list_free(cmds);
 }
 
@@ -3145,7 +3145,7 @@ command_mangen(void)
         curr = g_list_next(curr);
     }
 
-    printf("\nProcessed %d commands.\n\n", g_list_length(cmds));
+    printf("\nProcessed %u commands.\n\n", g_list_length(cmds));
 
     g_list_free(cmds);
 }
diff --git a/src/command/cmd_funcs.c b/src/command/cmd_funcs.c
index f12c9038..67815bc6 100644
--- a/src/command/cmd_funcs.c
+++ b/src/command/cmd_funcs.c
@@ -2271,7 +2271,7 @@ cmd_group(ProfWin* window, const char* const command, gchar** args)
         if (curr) {
             cons_show("Groups:");
             while (curr) {
-                cons_show("  %s", curr->data);
+                cons_show("  %s", (char*)curr->data);
                 curr = g_list_next(curr);
             }
 
@@ -3109,7 +3109,7 @@ cmd_blocked(ProfWin* window, const char* const command, gchar** args)
     if (curr) {
         cons_show("Blocked users:");
         while (curr) {
-            cons_show("  %s", curr->data);
+            cons_show("  %s", (char*)curr->data);
             curr = g_list_next(curr);
         }
     } else {
@@ -5190,7 +5190,7 @@ cmd_charset(ProfWin* window, const char* const command, gchar** args)
     if (codeset) {
         cons_show("  CODESET:    %s", codeset);
     }
-    cons_show("  MB_CUR_MAX: %d", MB_CUR_MAX);
+    cons_show("  MB_CUR_MAX: %zu", MB_CUR_MAX);
     cons_show("  MB_LEN_MAX: %d", MB_LEN_MAX);
 
     return TRUE;
@@ -5624,7 +5624,7 @@ cmd_notify(ProfWin* window, const char* const command, gchar** args)
                     cons_show("No room notification triggers");
                 }
                 while (curr) {
-                    cons_show("  %s", curr->data);
+                    cons_show("  %s", (char*)curr->data);
                     curr = g_list_next(curr);
                 }
                 g_list_free_full(triggers, free);
@@ -6299,7 +6299,7 @@ cmd_reconnect(ProfWin* window, const char* const command, gchar** args)
     } else if (strtoi_range(value, &intval, 0, INT_MAX, &err_msg)) {
         prefs_set_reconnect(intval);
         if (intval == 0) {
-            cons_show("Reconnect disabled.", intval);
+            cons_show("Reconnect disabled.");
         } else {
             cons_show("Reconnect interval set to %d seconds.", intval);
         }
@@ -6858,7 +6858,7 @@ cmd_plugins_install(ProfWin* window, const char* const command, gchar** args)
                 cons_show("");
                 cons_show("Installed and loaded plugins (%u):", g_slist_length(curr));
                 while (curr) {
-                    cons_show("  %s", curr->data);
+                    cons_show("  %s", (char*)curr->data);
                     curr = g_slist_next(curr);
                 }
             }
@@ -6867,7 +6867,7 @@ cmd_plugins_install(ProfWin* window, const char* const command, gchar** args)
                 cons_show("");
                 cons_show("Failed installs (%u):", g_slist_length(curr));
                 while (curr) {
-                    cons_show("  %s", curr->data);
+                    cons_show("  %s", (char*)curr->data);
                     curr = g_slist_next(curr);
                 }
             }
@@ -6969,7 +6969,7 @@ cmd_plugins_load(ProfWin* window, const char* const command, gchar** args)
             cons_show("Loaded plugins:");
             GSList* curr = loaded;
             while (curr) {
-                cons_show("  %s", curr->data);
+                cons_show("  %s", (char*)curr->data);
                 curr = g_slist_next(curr);
             }
             g_slist_free_full(loaded, g_free);
@@ -7101,7 +7101,7 @@ cmd_plugins(ProfWin* window, const char* const command, gchar** args)
         GSList* curr = unloaded_plugins;
         cons_show("The following plugins already installed and can be loaded:");
         while (curr) {
-            cons_show("  %s", curr->data);
+            cons_show("  %s", (char*)curr->data);
             curr = g_slist_next(curr);
         }
         g_slist_free_full(unloaded_plugins, g_free);
@@ -7111,7 +7111,7 @@ cmd_plugins(ProfWin* window, const char* const command, gchar** args)
         GList* curr = plugins;
         cons_show("Loaded plugins:");
         while (curr) {
-            cons_show("  %s", curr->data);
+            cons_show("  %s", (char*)curr->data);
             curr = g_list_next(curr);
         }
         g_list_free(plugins);
diff --git a/src/config/account.c b/src/config/account.c
index 296b831e..65e28839 100644
--- a/src/config/account.c
+++ b/src/config/account.c
@@ -189,7 +189,7 @@ account_eval_password(ProfAccount* account)
 
     int exit_status = pclose(stream);
     if (exit_status > 0) {
-        log_error("Command for `eval_password` returned error status (%s).",
+        log_error("Command for `eval_password` returned error status (%d).",
                   exit_status);
         return FALSE;
     } else if (exit_status < 0) {
diff --git a/src/log.h b/src/log.h
index 6da8ebcc..2cb044ee 100644
--- a/src/log.h
+++ b/src/log.h
@@ -54,9 +54,13 @@ void log_init(log_level_t filter, const char* const log_file);
 log_level_t log_get_filter(void);
 void log_close(void);
 const gchar* get_log_file_location(void);
+G_GNUC_PRINTF(1, 2)
 void log_debug(const char* const msg, ...);
+G_GNUC_PRINTF(1, 2)
 void log_info(const char* const msg, ...);
+G_GNUC_PRINTF(1, 2)
 void log_warning(const char* const msg, ...);
+G_GNUC_PRINTF(1, 2)
 void log_error(const char* const msg, ...);
 void log_msg(log_level_t level, const char* const area, const char* const msg);
 int log_level_from_string(char* log_level, log_level_t* level);
diff --git a/src/omemo/omemo.c b/src/omemo/omemo.c
index 59f2d82a..88864b26 100644
--- a/src/omemo/omemo.c
+++ b/src/omemo/omemo.c
@@ -537,7 +537,7 @@ omemo_set_device_list(const char* const from, GList* device_list)
                         g_hash_table_iter_init(&iter, known_identities);
                         while (g_hash_table_iter_next(&iter, &key, &value)) {
                             if (device_id->data == value) {
-                                cons_show("OMEMO: Adding firstusage trust for %s device %d - Fingerprint %s", jid->barejid, device_id->data, omemo_format_fingerprint(key));
+                                cons_show("OMEMO: Adding firstusage trust for %s device %d - Fingerprint %s", jid->barejid, GPOINTER_TO_INT(device_id->data), omemo_format_fingerprint(key));
                                 omemo_trust(jid->barejid, omemo_format_fingerprint(key));
                             }
                         }
@@ -744,8 +744,8 @@ omemo_on_message_send(ProfWin* win, const char* const message, gboolean request_
         GList* recipient_device_id = NULL;
         recipient_device_id = g_hash_table_lookup(omemo_ctx.device_list, recipients_iter->data);
         if (!recipient_device_id) {
-            log_warning("[OMEMO][SEND] cannot find device ids for %s", recipients_iter->data);
-            win_println(win, THEME_ERROR, "!", "Can't find a OMEMO device id for %s.\n", recipients_iter->data);
+            log_warning("[OMEMO][SEND] cannot find device ids for %s", (char*)recipients_iter->data);
+            win_println(win, THEME_ERROR, "!", "Can't find a OMEMO device id for %s.\n", (char*)recipients_iter->data);
             continue;
         }
 
@@ -769,7 +769,7 @@ omemo_on_message_send(ProfWin* win, const char* const message, gboolean request_
                 }
             }
 
-            log_debug("[OMEMO][SEND] recipients with device id %d for %s", GPOINTER_TO_INT(device_ids_iter->data), recipients_iter->data);
+            log_debug("[OMEMO][SEND] recipients with device id %d for %s", GPOINTER_TO_INT(device_ids_iter->data), (char*)recipients_iter->data);
             res = session_cipher_create(&cipher, omemo_ctx.store, &address, omemo_ctx.signal);
             if (res != SG_SUCCESS) {
                 log_error("[OMEMO][SEND] cannot create cipher for %s device id %d - code: %d", address.name, address.device_id, res);
@@ -1304,7 +1304,7 @@ _handle_own_device_list(const char* const jid, GList* device_list)
 {
     // We didn't find the own device id -> publish
     if (!g_list_find(device_list, GINT_TO_POINTER(omemo_ctx.device_id))) {
-        cons_show("Could not find own OMEMO device ID. Going to publish own device ID: %d", GINT_TO_POINTER(omemo_ctx.device_id));
+        cons_show("Could not find own OMEMO device ID. Going to publish own device ID: %d", omemo_ctx.device_id);
         log_debug("[OMEMO] No device ID for our device. Publishing device list");
         device_list = g_list_copy(device_list);
         device_list = g_list_append(device_list, GINT_TO_POINTER(omemo_ctx.device_id));
diff --git a/src/plugins/api.c b/src/plugins/api.c
index 7b6b8371..f96eb40a 100644
--- a/src/plugins/api.c
+++ b/src/plugins/api.c
@@ -532,7 +532,7 @@ api_encryption_reset(const char* const barejid)
 
     ProfChatWin* chatwin = wins_get_chat(barejid);
     if (chatwin == NULL) {
-        log_warning("%s", "api_encryption_reset failed, could not find chat window for %s", barejid);
+        log_warning("api_encryption_reset failed, could not find chat window for %s", barejid);
         return;
     }
 
@@ -566,7 +566,7 @@ api_chat_set_titlebar_enctext(const char* const barejid, const char* const encte
 
     ProfChatWin* chatwin = wins_get_chat(barejid);
     if (chatwin == NULL) {
-        log_warning("%s", "api_chat_set_titlebar_enctext failed, could not find chat window for %s", barejid);
+        log_warning("api_chat_set_titlebar_enctext failed, could not find chat window for %s", barejid);
         return 0;
     }
 
@@ -585,7 +585,7 @@ api_chat_unset_titlebar_enctext(const char* const barejid)
 
     ProfChatWin* chatwin = wins_get_chat(barejid);
     if (chatwin == NULL) {
-        log_warning("%s", "api_chat_unset_titlebar_enctext failed, could not find chat window for %s", barejid);
+        log_warning("api_chat_unset_titlebar_enctext failed, could not find chat window for %s", barejid);
         return 0;
     }
 
@@ -614,7 +614,7 @@ api_chat_set_incoming_char(const char* const barejid, const char* const ch)
 
     ProfChatWin* chatwin = wins_get_chat(barejid);
     if (chatwin == NULL) {
-        log_warning("%s", "api_chat_set_incoming_char failed, could not find chat window for %s", barejid);
+        log_warning("api_chat_set_incoming_char failed, could not find chat window for %s", barejid);
         return 0;
     }
 
@@ -633,7 +633,7 @@ api_chat_unset_incoming_char(const char* const barejid)
 
     ProfChatWin* chatwin = wins_get_chat(barejid);
     if (chatwin == NULL) {
-        log_warning("%s", "api_chat_unset_incoming_char failed, could not find chat window for %s", barejid);
+        log_warning("api_chat_unset_incoming_char failed, could not find chat window for %s", barejid);
         return 0;
     }
 
@@ -662,7 +662,7 @@ api_chat_set_outgoing_char(const char* const barejid, const char* const ch)
 
     ProfChatWin* chatwin = wins_get_chat(barejid);
     if (chatwin == NULL) {
-        log_warning("%s", "api_chat_set_outgoing_char failed, could not find chat window for %s", barejid);
+        log_warning("api_chat_set_outgoing_char failed, could not find chat window for %s", barejid);
         return 0;
     }
 
@@ -681,7 +681,7 @@ api_chat_unset_outgoing_char(const char* const barejid)
 
     ProfChatWin* chatwin = wins_get_chat(barejid);
     if (chatwin == NULL) {
-        log_warning("%s", "api_chat_unset_outgoing_char failed, could not find chat window for %s", barejid);
+        log_warning("api_chat_unset_outgoing_char failed, could not find chat window for %s", barejid);
         return 0;
     }
 
@@ -705,7 +705,7 @@ api_room_set_titlebar_enctext(const char* const roomjid, const char* const encte
 
     ProfMucWin* mucwin = wins_get_muc(roomjid);
     if (mucwin == NULL) {
-        log_warning("%s", "api_room_set_titlebar_enctext failed, could not find room window for %s", roomjid);
+        log_warning("api_room_set_titlebar_enctext failed, could not find room window for %s", roomjid);
         return 0;
     }
 
@@ -724,7 +724,7 @@ api_room_unset_titlebar_enctext(const char* const roomjid)
 
     ProfMucWin* mucwin = wins_get_muc(roomjid);
     if (mucwin == NULL) {
-        log_warning("%s", "api_room_unset_titlebar_enctext failed, could not find room window for %s", roomjid);
+        log_warning("api_room_unset_titlebar_enctext failed, could not find room window for %s", roomjid);
         return 0;
     }
 
@@ -753,7 +753,7 @@ api_room_set_message_char(const char* const roomjid, const char* const ch)
 
     ProfMucWin* mucwin = wins_get_muc(roomjid);
     if (mucwin == NULL) {
-        log_warning("%s", "api_room_set_message_char failed, could not find room window for %s", roomjid);
+        log_warning("api_room_set_message_char failed, could not find room window for %s", roomjid);
         return 0;
     }
 
@@ -772,7 +772,7 @@ api_room_unset_message_char(const char* const roomjid)
 
     ProfMucWin* mucwin = wins_get_muc(roomjid);
     if (mucwin == NULL) {
-        log_warning("%s", "api_room_unset_message_char failed, could not find room window for %s", roomjid);
+        log_warning("api_room_unset_message_char failed, could not find room window for %s", roomjid);
         return 0;
     }
 
@@ -796,7 +796,7 @@ api_chat_show(const char* const barejid, const char* message)
 
     ProfChatWin* chatwin = wins_get_chat(barejid);
     if (chatwin == NULL) {
-        log_warning("%s", "api_chat_show failed, could not find chat window for %s", barejid);
+        log_warning("api_chat_show failed, could not find chat window for %s", barejid);
         return 0;
     }
 
@@ -832,7 +832,7 @@ api_chat_show_themed(const char* const barejid, const char* const group, const c
 
     ProfChatWin* chatwin = wins_get_chat(barejid);
     if (chatwin == NULL) {
-        log_warning("%s", "api_chat_show_themed failed, could not find chat window for %s", barejid);
+        log_warning("api_chat_show_themed failed, could not find chat window for %s", barejid);
         return 0;
     }
 
@@ -859,7 +859,7 @@ api_room_show(const char* const roomjid, const char* message)
 
     ProfMucWin* mucwin = wins_get_muc(roomjid);
     if (mucwin == NULL) {
-        log_warning("%s", "api_room_show failed, could not find room window for %s", roomjid);
+        log_warning("api_room_show failed, could not find room window for %s", roomjid);
         return 0;
     }
 
@@ -895,7 +895,7 @@ api_room_show_themed(const char* const roomjid, const char* const group, const c
 
     ProfMucWin* mucwin = wins_get_muc(roomjid);
     if (mucwin == NULL) {
-        log_warning("%s", "api_room_show_themed failed, could not find room window for %s", roomjid);
+        log_warning("api_room_show_themed failed, could not find room window for %s", roomjid);
         return 0;
     }
 
diff --git a/src/ui/chatwin.c b/src/ui/chatwin.c
index 3e6af296..4a0c1498 100644
--- a/src/ui/chatwin.c
+++ b/src/ui/chatwin.c
@@ -303,7 +303,7 @@ chatwin_incoming_msg(ProfChatWin* chatwin, ProfMessage* message, gboolean win_cr
     assert(chatwin != NULL);
 
     if (message->plain == NULL) {
-        log_error("chatwin_incoming_msg: Message with no plain field from: %s", message->from_jid);
+        log_error("chatwin_incoming_msg: Message with no plain field from: %s", message->from_jid->fulljid);
         return;
     }
 
diff --git a/src/ui/console.c b/src/ui/console.c
index d1104fa0..55021ed8 100644
--- a/src/ui/console.c
+++ b/src/ui/console.c
@@ -470,10 +470,10 @@ cons_show_wins(gboolean unread)
 
     GSList* curr = window_strings;
     while (curr) {
-        if (g_strstr_len(curr->data, strlen(curr->data), " unread") > 0) {
-            win_println(console, THEME_CMD_WINS_UNREAD, "-", "%s", curr->data);
+        if (g_strstr_len((char*)curr->data, strlen((char*)curr->data), " unread") > 0) {
+            win_println(console, THEME_CMD_WINS_UNREAD, "-", "%s", (char*)curr->data);
         } else {
-            win_println(console, THEME_DEFAULT, "-", "%s", curr->data);
+            win_println(console, THEME_DEFAULT, "-", "%s", (char*)curr->data);
         }
         curr = g_slist_next(curr);
     }
@@ -491,10 +491,10 @@ cons_show_wins_attention()
 
     GSList* curr = window_strings;
     while (curr) {
-        if (g_strstr_len(curr->data, strlen(curr->data), " unread") > 0) {
-            win_println(console, THEME_CMD_WINS_UNREAD, "-", "%s", curr->data);
+        if (g_strstr_len((char*)curr->data, strlen((char*)curr->data), " unread") > 0) {
+            win_println(console, THEME_CMD_WINS_UNREAD, "-", "%s", (char*)curr->data);
         } else {
-            win_println(console, THEME_DEFAULT, "-", "%s", curr->data);
+            win_println(console, THEME_DEFAULT, "-", "%s", (char*)curr->data);
         }
         curr = g_slist_next(curr);
     }
@@ -512,7 +512,7 @@ cons_show_room_invites(GList* invites)
     } else {
         cons_show("Chat room invites, use /join or /decline commands:");
         while (invites) {
-            cons_show("  %s", invites->data);
+            cons_show("  %s", (char*)invites->data);
             invites = g_list_next(invites);
         }
     }
@@ -591,7 +591,7 @@ cons_show_caps(const char* const fulljid, resource_presence_t presence)
             win_println(console, THEME_DEFAULT, "-", "Features:");
             GSList* feature = caps->features;
             while (feature) {
-                win_println(console, THEME_DEFAULT, "-", " %s", feature->data);
+                win_println(console, THEME_DEFAULT, "-", " %s", (char*)feature->data);
                 feature = g_slist_next(feature);
             }
         }
@@ -611,10 +611,10 @@ cons_show_received_subs(void)
     if (received == NULL) {
         cons_show("No outstanding subscription requests.");
     } else {
-        cons_show("Outstanding subscription requests from:",
+        cons_show("Outstanding subscription requests from (%d):",
                   g_list_length(received));
         while (received) {
-            cons_show("  %s", received->data);
+            cons_show("  %s", (char*)received->data);
             received = g_list_next(received);
         }
         g_list_free_full(received, g_free);
@@ -782,7 +782,7 @@ cons_show_disco_info(const char* jid, GSList* identities, GSList* features)
             cons_show("  Features:");
         }
         while (features) {
-            cons_show("    %s", features->data);
+            cons_show("    %s", (char*)features->data);
             features = g_slist_next(features);
         }
 
@@ -2297,7 +2297,7 @@ cons_show_themes(GSList* themes)
     } else {
         cons_show("Available themes:");
         while (themes) {
-            cons_show("%s", themes->data);
+            cons_show("%s", (char*)themes->data);
             themes = g_slist_next(themes);
         }
     }
@@ -2315,7 +2315,7 @@ cons_show_scripts(GSList* scripts)
     } else {
         cons_show("Scripts:");
         while (scripts) {
-            cons_show("%s", scripts->data);
+            cons_show("%s", (char*)scripts->data);
             scripts = g_slist_next(scripts);
         }
     }
@@ -2333,7 +2333,7 @@ cons_show_script(const char* const script, GSList* commands)
     } else {
         cons_show("%s:", script);
         while (commands) {
-            cons_show("  %s", commands->data);
+            cons_show("  %s", (char*)commands->data);
             commands = g_slist_next(commands);
         }
     }
diff --git a/src/ui/mucwin.c b/src/ui/mucwin.c
index b306aab2..10f8a2ca 100644
--- a/src/ui/mucwin.c
+++ b/src/ui/mucwin.c
@@ -218,7 +218,7 @@ mucwin_room_disco_info(ProfMucWin* mucwin, GSList* identities, GSList* features)
             win_println(window, THEME_DEFAULT, "!", "Features:");
         }
         while (features) {
-            win_println(window, THEME_DEFAULT, "!", "  %s", features->data);
+            win_println(window, THEME_DEFAULT, "!", "  %s", (char*)features->data);
             features = g_slist_next(features);
         }
         win_println(window, THEME_DEFAULT, "-", "");
@@ -534,7 +534,7 @@ mucwin_incoming_msg(ProfMucWin* mucwin, const ProfMessage* const message, GSList
     int flags = 0;
 
     if (message->plain == NULL) {
-        log_error("mucwin_incoming_msg: Message with no plain field from: %s", message->from_jid);
+        log_error("mucwin_incoming_msg: Message with no plain field from: %s", message->from_jid->fulljid);
         return;
     }
 
diff --git a/src/ui/privwin.c b/src/ui/privwin.c
index 81aaaa09..b758bace 100644
--- a/src/ui/privwin.c
+++ b/src/ui/privwin.c
@@ -52,7 +52,7 @@ privwin_incoming_msg(ProfPrivateWin* privatewin, ProfMessage* message)
     assert(privatewin != NULL);
 
     if (message->plain == NULL) {
-        log_error("privwin_incoming_msg: Message with no plain field from: %s", message->from_jid);
+        log_error("privwin_incoming_msg: Message with no plain field from: %s", message->from_jid->fulljid);
         return;
     }
 
diff --git a/src/ui/ui.h b/src/ui/ui.h
index 1af8529e..aa8b5ea8 100644
--- a/src/ui/ui.h
+++ b/src/ui/ui.h
@@ -244,7 +244,9 @@ char* inp_readline(void);
 void inp_nonblocking(gboolean reset);
 
 // Console window
+G_GNUC_PRINTF(1, 2)
 void cons_show(const char* const msg, ...);
+G_GNUC_PRINTF(2, 3)
 void cons_show_padded(int pad, const char* const msg, ...);
 void cons_about(void);
 void cons_help(void);
@@ -263,7 +265,9 @@ void cons_show_pgp_prefs(void);
 void cons_show_omemo_prefs(void);
 void cons_show_ox_prefs(void);
 void cons_show_account(ProfAccount* account);
+G_GNUC_PRINTF(1, 2)
 void cons_debug(const char* const msg, ...);
+G_GNUC_PRINTF(1, 2)
 void cons_show_error(const char* const cmd, ...);
 void cons_show_contacts(GSList* list);
 void cons_show_roster(GSList* list);
@@ -393,16 +397,24 @@ void win_show_subwin(ProfWin* window);
 void win_refresh_without_subwin(ProfWin* window);
 void win_refresh_with_subwin(ProfWin* window);
 
+G_GNUC_PRINTF(4, 5)
 void win_print(ProfWin* window, theme_item_t theme_item, const char* show_char, const char* const message, ...);
+G_GNUC_PRINTF(4, 5)
 void win_println(ProfWin* window, theme_item_t theme_item, const char* show_char, const char* const message, ...);
+G_GNUC_PRINTF(3, 4)
 void win_println_indent(ProfWin* window, int pad, const char* const message, ...);
 
+G_GNUC_PRINTF(4, 0)
 void win_println_va(ProfWin* window, theme_item_t theme_item, const char* show_char, const char* const message, va_list arg);
 
+G_GNUC_PRINTF(3, 4)
 void win_append(ProfWin* window, theme_item_t theme_item, const char* const message, ...);
+G_GNUC_PRINTF(3, 4)
 void win_appendln(ProfWin* window, theme_item_t theme_item, const char* const message, ...);
 
+G_GNUC_PRINTF(3, 4)
 void win_append_highlight(ProfWin* window, theme_item_t theme_item, const char* const message, ...);
+G_GNUC_PRINTF(3, 4)
 void win_appendln_highlight(ProfWin* window, theme_item_t theme_item, const char* const message, ...);
 
 gchar* win_get_title(ProfWin* window);
@@ -416,6 +428,7 @@ void win_clear(ProfWin* window);
 char* win_get_tab_identifier(ProfWin* window);
 gchar* win_to_string(ProfWin* window);
 void win_command_list_error(ProfWin* window, const char* const error);
+G_GNUC_PRINTF(3, 4)
 void win_command_exec_error(ProfWin* window, const char* const command, const char* const error, ...);
 void win_handle_command_list(ProfWin* window, GSList* cmds);
 void win_handle_command_exec_status(ProfWin* window, const char* const type, const char* const value);
diff --git a/src/xmpp/connection.c b/src/xmpp/connection.c
index 3c38f744..aa51b5e9 100644
--- a/src/xmpp/connection.c
+++ b/src/xmpp/connection.c
@@ -239,7 +239,7 @@ _conn_apply_settings(const char* const jid, const char* const passwd, const char
     }
 
     if (xmpp_conn_set_flags(conn.xmpp_conn, flags)) {
-        log_error("libstrophe doesn't accept this combination of flags: 0x%x", flags);
+        log_error("libstrophe doesn't accept this combination of flags: 0x%lx", flags);
         conn.conn_status = JABBER_DISCONNECTED;
         return FALSE;
     }
diff --git a/src/xmpp/iq.c b/src/xmpp/iq.c
index 34795692..24b5f1be 100644
--- a/src/xmpp/iq.c
+++ b/src/xmpp/iq.c
@@ -921,7 +921,7 @@ _caps_response_id_handler(xmpp_stanza_t* const stanza, void* const userdata)
     // handle error responses
     if (g_strcmp0(type, STANZA_TYPE_ERROR) == 0) {
         auto_char char* error_message = stanza_get_error_message(stanza);
-        log_warning("Error received for capabilities response from %s: ", from, error_message);
+        log_warning("Error received for capabilities response from %s: %s", from, error_message);
         return 0;
     }
 
@@ -996,7 +996,7 @@ _caps_response_for_jid_id_handler(xmpp_stanza_t* const stanza, void* const userd
     // handle error responses
     if (g_strcmp0(type, STANZA_TYPE_ERROR) == 0) {
         auto_char char* error_message = stanza_get_error_message(stanza);
-        log_warning("Error received for capabilities response from %s: ", from, error_message);
+        log_warning("Error received for capabilities response from %s: %s", from, error_message);
         return 0;
     }
 
@@ -1054,7 +1054,7 @@ _caps_response_legacy_id_handler(xmpp_stanza_t* const stanza, void* const userda
     // handle error responses
     if (g_strcmp0(type, STANZA_TYPE_ERROR) == 0) {
         auto_char char* error_message = stanza_get_error_message(stanza);
-        log_warning("Error received for capabilities response from %s: ", from, error_message);
+        log_warning("Error received for capabilities response from %s: %s", from, error_message);
         return 0;
     }
 
@@ -1254,7 +1254,7 @@ _command_exec_response_handler(xmpp_stanza_t* const stanza, void* const userdata
     if (g_strcmp0(type, STANZA_TYPE_ERROR) == 0) {
         auto_char char* error_message = stanza_get_error_message(stanza);
         log_debug("Error executing command %s for %s: %s", command, from, error_message);
-        win_command_exec_error(win, command, error_message);
+        win_command_exec_error(win, command, "%s", error_message);
         return 0;
     }
 
diff --git a/src/xmpp/presence.c b/src/xmpp/presence.c
index 8916235a..5249a1c9 100644
--- a/src/xmpp/presence.c
+++ b/src/xmpp/presence.c
@@ -501,7 +501,7 @@ _subscribe_handler(xmpp_stanza_t* const stanza)
 {
     const char* from = xmpp_stanza_get_from(stanza);
     if (!from) {
-        log_warning("Subscribe presence handler received with no from attribute", from);
+        log_warning("Subscribe presence handler received with no from attribute");
     }
     log_debug("Subscribe presence handler fired for %s", from);