diff --git a/tests/posix/common/src/pthread.c b/tests/posix/common/src/pthread.c
index 3801d3b4186..035730ee4dc 100644
--- a/tests/posix/common/src/pthread.c
+++ b/tests/posix/common/src/pthread.c
@@ -404,9 +404,8 @@ ZTEST(pthread, test_pthread_timedjoin)
 	struct timespec not_done;
 	struct timespec done;
 	struct timespec invalid[] = {
-		[0] = {.tv_sec = -1},
-		[1] = {.tv_nsec = -1},
-		[2] = {.tv_nsec = NSEC_PER_SEC},
+		{.tv_nsec = -1},
+		{.tv_nsec = NSEC_PER_SEC},
 	};
 
 	/* setup timespecs when the thread is still running and when it is done */
@@ -426,7 +425,7 @@ ZTEST(pthread, test_pthread_timedjoin)
 	/* Creating a thread that exits after 200ms*/
 	zassert_ok(pthread_create(&th, NULL, timedjoin_thread, INT_TO_POINTER(sleep_duration_ms)));
 
-	/* pthread_timedjoin-np must return -EINVAL for invalid struct timespecs */
+	/* pthread_timedjoin-np must return EINVAL for invalid struct timespecs */
 	zassert_equal(pthread_timedjoin_np(th, &ret, NULL), EINVAL);
 	for (size_t i = 0; i < ARRAY_SIZE(invalid); ++i) {
 		zassert_equal(pthread_timedjoin_np(th, &ret, &invalid[i]), EINVAL);