diff --git a/plugins/obs-ffmpeg/ffmpeg-mux/ffmpeg-mux.c b/plugins/obs-ffmpeg/ffmpeg-mux/ffmpeg-mux.c
index 368877e60..72763d814 100644
--- a/plugins/obs-ffmpeg/ffmpeg-mux/ffmpeg-mux.c
+++ b/plugins/obs-ffmpeg/ffmpeg-mux/ffmpeg-mux.c
@@ -237,7 +237,9 @@ static void ffmpeg_log_callback(void *param, int level, const char *format,
 
 	vsnprintf(out_buffer, sizeof(out_buffer), format, args);
 	dstr_copy(&out, out_buffer);
-	dstr_replace(&out, global_stream_key, "{stream_key}");
+	if (global_stream_key && *global_stream_key) {
+		dstr_replace(&out, global_stream_key, "{stream_key}");
+	}
 
 	switch (level) {
 	case AV_LOG_INFO: