diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 2044324b755a..2a6f33cd888c 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -74,6 +74,7 @@ static pid_t perf_event__get_comm_tgid(pid_t pid, char *comm, size_t len)
 			if (size >= len)
 				size = len - 1;
 			memcpy(comm, name, size);
+			comm[size] = '\0';
 
 		} else if (memcmp(bf, "Tgid:", 5) == 0) {
 			char *tgids = bf + 5;