diff --git a/util/log.c b/util/log.c
index 1ca13059ee..4316fe74ee 100644
--- a/util/log.c
+++ b/util/log.c
@@ -113,6 +113,7 @@ void qemu_set_log_filename(const char *filename, Error **errp)
 {
     char *pidstr;
     g_free(logfilename);
+    logfilename = NULL;
 
     pidstr = strstr(filename, "%");
     if (pidstr) {