diff --git a/tools/testing/selftests/cgroup/cgroup_util.c b/tools/testing/selftests/cgroup/cgroup_util.c
index 8a637ca7d73a4173c647cade618cca111cbb53d2..05853b0b883181fa4dc784166f2828fb17cbbedf 100644
--- a/tools/testing/selftests/cgroup/cgroup_util.c
+++ b/tools/testing/selftests/cgroup/cgroup_util.c
@@ -106,7 +106,7 @@ int cg_read_strcmp(const char *cgroup, const char *control,
 
 	/* Handle the case of comparing against empty string */
 	if (!expected)
-		size = 32;
+		return -1;
 	else
 		size = strlen(expected) + 1;