diff --git a/tests/posix/common/src/clock.c b/tests/posix/common/src/clock.c
index d36c74fe0ded3a..07a825434c5eba 100644
--- a/tests/posix/common/src/clock.c
+++ b/tests/posix/common/src/clock.c
@@ -217,10 +217,11 @@ ZTEST(clock, test_realtime)
 ZTEST(clock, test_clock_getcpuclockid)
 {
 	int ret = 0;
-	clockid_t clock_id;
+	clockid_t clock_id = CLOCK_INVALID;
 
 	ret = clock_getcpuclockid((pid_t)0, &clock_id);
 	zassert_equal(ret, 0, "POSIX clock_getcpuclock id failed");
+	zassert_equal(clock_id, CLOCK_PROCESS_CPUTIME_ID, "POSIX clock_getcpuclock id failed");
 
 	ret = clock_getcpuclockid((pid_t)2482, &clock_id);
 	zassert_equal(ret, EPERM, "POSIX clock_getcpuclock id failed");