diff --git a/tests/subsys/logging/log_core_additional/src/log_test.c b/tests/subsys/logging/log_core_additional/src/log_test.c
index e253dc7b70a..06473be49d5 100644
--- a/tests/subsys/logging/log_core_additional/src/log_test.c
+++ b/tests/subsys/logging/log_core_additional/src/log_test.c
@@ -20,6 +20,7 @@
 
 #define LOG_MODULE_NAME log_test
 LOG_MODULE_REGISTER(LOG_MODULE_NAME, LOG_LEVEL_INF);
+static K_SEM_DEFINE(log_sem, 0, 1);
 
 struct backend_cb {
 	/* count log messages handled by this backend */
@@ -34,6 +35,11 @@ struct backend_cb {
 	uint16_t exp_severity[4];
 	/* inform put() to check domain_id of message */
 	bool check_domain_id;
+	/* How many messages have been logged.
+	 * used in async mode, to make sure all logs have been handled by compare
+	 * counter with total_logs
+	 */
+	size_t total_logs;
 };
 
 static void put(struct log_backend const *const backend, struct log_msg *msg)
@@ -60,6 +66,11 @@ static void put(struct log_backend const *const backend, struct log_msg *msg)
 	}
 
 	cb->counter++;
+	if (IS_ENABLED(CONFIG_LOG_PROCESS_THREAD)) {
+		if (cb->counter == cb->total_logs) {
+			k_sem_give(&log_sem);
+		}
+	}
 	log_msg_put(msg);
 }
 
@@ -130,8 +141,8 @@ static void log_setup(bool backend2_enable)
 static bool log_test_process(bool bypass)
 {
 	if (IS_ENABLED(CONFIG_LOG_PROCESS_THREAD)) {
-		/* a dedicate thread handle log messages, wait for 1 second */
-		k_sleep(K_MSEC(1000));
+		/* waiting for all logs have been handled */
+		k_sem_take(&log_sem, K_FOREVER);
 		return false;
 	} else {
 		return log_process(bypass);
@@ -152,13 +163,14 @@ static void test_log_domain_id(void)
 	log_setup(false);
 
 	backend1_cb.check_domain_id = true;
+	backend1_cb.total_logs = 1;
 
 	LOG_INF("info message for domain id test");
 
 	while (log_test_process(false)) {
 	}
 
-	zassert_equal(1, backend1_cb.counter,
+	zassert_equal(backend1_cb.total_logs, backend1_cb.counter,
 		      "Unexpected amount of messages received by the backend");
 }
 
@@ -221,12 +233,13 @@ static void test_log_early_logging(void)
 
 		TC_PRINT("Activate backend with context");
 		memset(&backend1_cb, 0, sizeof(backend1_cb));
+		backend1_cb.total_logs = 3;
 		log_backend_enable(&backend1, &backend1_cb, LOG_LEVEL_DBG);
 
 		while (log_test_process(false)) {
 		}
 
-		zassert_equal(3, backend1_cb.counter,
+		zassert_equal(backend1_cb.total_logs, backend1_cb.counter,
 			      "Unexpected amount of messages received. %d",
 			      backend1_cb.counter);
 	}
@@ -253,11 +266,12 @@ static void test_log_severity(void)
 	LOG_INF("info message");
 	LOG_WRN("warning message");
 	LOG_ERR("error message");
+	backend1_cb.total_logs = 3;
 
 	while (log_test_process(false)) {
 	}
 
-	zassert_equal(3, backend1_cb.counter,
+	zassert_equal(backend1_cb.total_logs, backend1_cb.counter,
 		      "Unexpected amount of messages received by the backend.");
 }
 
@@ -298,11 +312,12 @@ static void test_log_timestamping(void)
 	LOG_INF("test timestamp");
 	LOG_INF("test timestamp");
 	LOG_WRN("test timestamp");
+	backend1_cb.total_logs = 3;
 
 	while (log_test_process(false)) {
 	}
 
-	zassert_equal(3,
+	zassert_equal(backend1_cb.total_logs,
 		      backend1_cb.counter,
 		      "Unexpected amount of messages received by the backend.");
 }