diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 83d38637afe3..1700130adedb 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -1258,6 +1258,7 @@ int machines__create_guest_kernel_maps(struct machines *machines)
 				/* Filter out . and .. */
 				continue;
 			}
+			errno = 0;
 			pid = (pid_t)strtol(namelist[i]->d_name, &endp, 10);
 			if ((*endp != '\0') ||
 			    (endp == namelist[i]->d_name) ||