diff --git a/common/av_log.c b/common/av_log.c
index 7e0b271c81..bfd9a836e8 100644
--- a/common/av_log.c
+++ b/common/av_log.c
@@ -131,12 +131,17 @@ static void mp_msg_av_log_callback(void *ptr, int level, const char *fmt,
     struct mp_log *log = get_av_log(ptr);
 
     if (mp_msg_test(log, mp_level)) {
+        char buffer[4096] = "";
+        int pos = 0;
         const char *prefix = avc ? avc->item_name(ptr) : NULL;
         if (log_print_prefix && prefix)
-            mp_msg(log, mp_level, "%s: ", prefix);
+            pos = snprintf(buffer, sizeof(buffer), "%s: ", prefix);
         log_print_prefix = fmt[strlen(fmt) - 1] == '\n';
 
-        mp_msg_va(log, mp_level, fmt, vl);
+        pos = MPMIN(MPMAX(pos, 0), sizeof(buffer));
+        vsnprintf(buffer + pos, sizeof(buffer) - pos, fmt, vl);
+
+        mp_msg(log, mp_level, "%s", buffer);
     }
 
     pthread_mutex_unlock(&log_lock);