diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 2880e2226fdb..8ab0d7da956b 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -346,7 +346,8 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool,
 		if (!strcmp(execname, ""))
 			strcpy(execname, anonstr);
 
-		if (!strncmp(execname, hugetlbfs_mnt, hugetlbfs_mnt_len)) {
+		if (hugetlbfs_mnt_len &&
+		    !strncmp(execname, hugetlbfs_mnt, hugetlbfs_mnt_len)) {
 			strcpy(execname, anonstr);
 			event->mmap2.flags |= MAP_HUGETLB;
 		}