diff --git a/src/backend/postmaster/syslogger.c b/src/backend/postmaster/syslogger.c
index 34b16ba3bb3..d1f56b95a43 100644
--- a/src/backend/postmaster/syslogger.c
+++ b/src/backend/postmaster/syslogger.c
@@ -1258,7 +1258,7 @@ logfile_rotate_dest(bool time_based_rotation, int size_rotation_for,
 					pg_time_t fntime, int target_dest,
 					char **last_file_name, FILE **logFile)
 {
-	char	   *logFileExt;
+	char	   *logFileExt = NULL;
 	char	   *filename;
 	FILE	   *fh;