diff --git a/subsys/portability/cmsis_rtos_v2/event_flags.c b/subsys/portability/cmsis_rtos_v2/event_flags.c
index fc3d50f067dcd..a9eb3dfb0ef2b 100644
--- a/subsys/portability/cmsis_rtos_v2/event_flags.c
+++ b/subsys/portability/cmsis_rtos_v2/event_flags.c
@@ -57,13 +57,16 @@ osEventFlagsId_t osEventFlagsNew(const osEventFlagsAttr_t *attr)
 uint32_t osEventFlagsSet(osEventFlagsId_t ef_id, uint32_t flags)
 {
 	struct cmsis_rtos_event_cb *events = (struct cmsis_rtos_event_cb *)ef_id;
+	uint32_t rv;
+
 	if ((ef_id == NULL) || (flags & osFlagsError)) {
 		return osFlagsErrorParameter;
 	}
 
-	k_event_post(&events->z_event, flags);
+	rv = k_event_test(&events->z_event, 0xFFFFFFFF);
+	k_event_post(&events->z_event, flags & ~rv);
 
-	return k_event_test(&events->z_event, 0xFFFFFFFF);
+	return flags & ~rv;
 }
 
 /**
@@ -79,7 +82,7 @@ uint32_t osEventFlagsClear(osEventFlagsId_t ef_id, uint32_t flags)
 	}
 
 	rv = k_event_test(&events->z_event, 0xFFFFFFFF);
-	k_event_clear(&events->z_event, flags);
+	k_event_clear(&events->z_event, flags & rv);
 
 	return rv;
 }
@@ -91,6 +94,7 @@ uint32_t osEventFlagsWait(osEventFlagsId_t ef_id, uint32_t flags, uint32_t optio
 			  uint32_t timeout)
 {
 	struct cmsis_rtos_event_cb *events = (struct cmsis_rtos_event_cb *)ef_id;
+	uint32_t sub_opt = options & (osFlagsWaitAll | osFlagsNoClear);
 	uint32_t rv;
 	k_timeout_t event_timeout;
 
@@ -114,14 +118,21 @@ uint32_t osEventFlagsWait(osEventFlagsId_t ef_id, uint32_t flags, uint32_t optio
 		event_timeout = K_TICKS(timeout);
 	}
 
-	if ((options & osFlagsWaitAll) != 0) {
+	switch (sub_opt) {
+	case osFlagsWaitAll | osFlagsNoClear:
 		rv = k_event_wait_all(&events->z_event, flags, false, event_timeout);
-	} else {
+		break;
+	case osFlagsWaitAll:
+		rv = k_event_wait_all_safe(&events->z_event, flags, false, event_timeout);
+		break;
+	case osFlagsNoClear:
 		rv = k_event_wait(&events->z_event, flags, false, event_timeout);
-	}
-
-	if ((options & osFlagsNoClear) == 0) {
-		k_event_clear(&events->z_event, flags);
+		break;
+	case 0:
+		rv = k_event_wait_safe(&events->z_event, flags, false, event_timeout);
+		break;
+	default:
+		__ASSERT_NO_MSG(0);
 	}
 
 	if (rv != 0U) {
diff --git a/tests/subsys/portability/cmsis_rtos_v2/src/event_flags.c b/tests/subsys/portability/cmsis_rtos_v2/src/event_flags.c
index faa3b19bae414..a6e3e50ec38e5 100644
--- a/tests/subsys/portability/cmsis_rtos_v2/src/event_flags.c
+++ b/tests/subsys/portability/cmsis_rtos_v2/src/event_flags.c
@@ -32,16 +32,7 @@ static void thread2(void *arg)
 {
 	int flags = osEventFlagsSet((osEventFlagsId_t)arg, FLAG2);
 
-	/* Please note that as soon as the last flag that a thread is waiting
-	 * on is set, the control shifts to that thread and that thread may
-	 * choose to clear the flags as part of its osEventFlagsWait operation.
-	 * In this test case, the main thread is waiting for FLAG1 and FLAG2.
-	 * FLAG1 gets set first and then FLAG2 gets set. As soon as FLAG2 gets
-	 * set, control shifts to the waiting thread where osEventFlagsWait
-	 * clears FLAG1 and FLAG2 internally. When this thread eventually gets
-	 * scheduled we should hence check if FLAG2 is cleared.
-	 */
-	zassert_equal(flags & FLAG2, 0, "");
+	zassert_equal(flags & FLAG2, FLAG2, "");
 }
 
 static K_THREAD_STACK_DEFINE(test_stack1, STACKSZ);