diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7ef097e63..65bae90a9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -28,6 +28,7 @@ SPDX-License-Identifier: GPL-3.0-or-later
 - core: fix integer overflow with decimal numbers in calculation of expression
 - core: fix integer overflow in base32 encoding/decoding
 - core: fix buffer overflow in function util_parse_time
+- core: fix buffer overflow in function eval_syntax_highlight_colorize
 - core: fix memory leak in function util_parse_delay
 - irc: display nick changes and quit messages when option irc.look.ignore_tag_messages is enabled ([#2241](https://github.com/weechat/weechat/issues/2241))
 - perl: fix build when multiplicity is not available ([#2243](https://github.com/weechat/weechat/issues/2243))
diff --git a/src/core/core-eval.c b/src/core/core-eval.c
index 001111f25..438f274df 100644
--- a/src/core/core-eval.c
+++ b/src/core/core-eval.c
@@ -1574,7 +1574,8 @@ eval_syntax_highlight_colorize (const char *value)
             else if (ptr_value[0] == '-')
                 color--;
         }
-        ptr_value++;
+        if (ptr_value[0])
+            ptr_value++;
         if (config_num_eval_syntax_colors > 0)
         {
             string_dyn_concat (