diff --git a/src/test/core_log/TESTS.py b/src/test/core_log/TESTS.py
index 8b509638e2c..c84ad1578e3 100755
--- a/src/test/core_log/TESTS.py
+++ b/src/test/core_log/TESTS.py
@@ -46,3 +46,7 @@ class TEST5(CORE_LOG):
 
 class TEST6(CORE_LOG):
     test_case = 'test_happy_day'
+
+
+class TEST7(CORE_LOG):
+    test_case = 'test_set_custom_function'
diff --git a/src/test/core_log/core_log.c b/src/test/core_log/core_log.c
index 75aa59891f6..5801f02ef0c 100644
--- a/src/test/core_log/core_log.c
+++ b/src/test/core_log/core_log.c
@@ -2,7 +2,8 @@
 /* Copyright 2024, Intel Corporation */
 
 /*
- * core_log.c -- unit test for core_log() and core_log_va()
+ * core_log.c -- unit test for core_log(), core_log_va() and
+ * core_log_set_function()
  */
 
 #include <syslog.h>
@@ -172,11 +173,25 @@ test_level_gt_threshold(const struct test_case *tc, int argc, char *argv[])
 }
 
 static int
-test_happy_day(const struct test_case *tc, int argc, char *argv[])
+test_happy_day_helper(core_log_function *log_function)
 {
 	/* Pass the message all the way to the logging function. */
 	core_log_set_threshold(CORE_LOG_THRESHOLD, CORE_LOG_LEVEL_ERROR);
 
+	/*
+	 * Disable the validation as custom_log_function() may be called from
+	 * core_log_set_function().
+	 */
+	if (log_function == CORE_LOG_USE_DEFAULT_FUNCTION) {
+		FUNC_MOCK_RCOUNTER_SET(core_log_default_function,
+			NOT_VALIDATED_CALL);
+	} else {
+		FUNC_MOCK_RCOUNTER_SET(custom_log_function,
+			NOT_VALIDATED_CALL);
+	}
+
+	core_log_set_function(log_function);
+
 	reset_mocks();
 
 	/* set the expectations */
@@ -195,11 +210,30 @@ test_happy_day(const struct test_case *tc, int argc, char *argv[])
 	UT_ASSERTeq(RCOUNTER(last_error_msg_get), CALLED);
 	UT_ASSERTeq(RCOUNTER(vsnprintf), CALLED);
 	UT_ASSERTeq(RCOUNTER(__xpg_strerror_r), CALLED);
-	UT_ASSERTeq(RCOUNTER(core_log_default_function), CALLED);
+	if (log_function == CORE_LOG_USE_DEFAULT_FUNCTION) {
+		UT_ASSERTeq(RCOUNTER(core_log_default_function), CALLED);
+		UT_ASSERTeq(RCOUNTER(custom_log_function), NOT_CALLED);
+	} else {
+		UT_ASSERTeq(RCOUNTER(core_log_default_function), NOT_CALLED);
+		UT_ASSERTeq(RCOUNTER(custom_log_function), CALLED);
+	}
 
 	return NO_ARGS_CONSUMED;
 }
 
+static int
+test_happy_day(const struct test_case *tc, int argc, char *argv[])
+{
+	return test_happy_day_helper(CORE_LOG_USE_DEFAULT_FUNCTION);
+}
+
+/* Happy day scenario with custom logging function */
+static int
+test_set_custom_function(const struct test_case *tc, int argc, char *argv[])
+{
+	return test_happy_day_helper(custom_log_function);
+}
+
 static struct test_case test_cases[] = {
 	TEST_CASE(test_CORE_LOG_LEVEL_ERROR_LAST),
 	TEST_CASE(test_vsnprintf_fail),
@@ -208,6 +242,7 @@ static struct test_case test_cases[] = {
 	TEST_CASE(test_strerror_r_fail),
 	TEST_CASE(test_level_gt_threshold),
 	TEST_CASE(test_happy_day),
+	TEST_CASE(test_set_custom_function),
 };
 
 #define NTESTS ARRAY_SIZE(test_cases)
diff --git a/src/test/core_log/core_log_common.c b/src/test/core_log/core_log_common.c
index 727ce318fbf..63c1f7c1651 100644
--- a/src/test/core_log/core_log_common.c
+++ b/src/test/core_log/core_log_common.c
@@ -84,6 +84,34 @@ FUNC_MOCK_RUN_DEFAULT {
 }
 FUNC_MOCK_END
 
+FUNC_MOCK_NONSTATIC(custom_log_function, void, enum core_log_level level,
+	const char *file_name, const int line_no, const char *function_name,
+	const char *message)
+	FUNC_MOCK_RUN(VALIDATED_CALL) {
+		UT_ASSERTeq(level, Log_function_.exp_level);
+		UT_ASSERTstreq(file_name, FILE_NAME);
+		UT_ASSERTeq(line_no, LINE_NO);
+		UT_ASSERTstreq(function_name, FUNC_NAME);
+		if (Common.use_last_error_msg) {
+			UT_ASSERTeq(message, LAST_ERROR_MSG_MOCK);
+		} else {
+			UT_ASSERTne(message, LAST_ERROR_MSG_MOCK);
+		}
+		return;
+	}
+FUNC_MOCK_RUN_DEFAULT {
+	_FUNC_REAL(custom_log_function)(level, file_name, line_no,
+		function_name, message);
+}
+FUNC_MOCK_END
+
+void
+custom_log_function(enum core_log_level level, const char *file_name,
+	const int line_no, const char *function_name, const char *message)
+{
+	SUPPRESS_UNUSED(level, file_name, line_no, function_name, message);
+}
+
 /* helpers */
 
 void
@@ -93,6 +121,7 @@ reset_mocks(void)
 	FUNC_MOCK_RCOUNTER_SET(vsnprintf, VALIDATED_CALL);
 	FUNC_MOCK_RCOUNTER_SET(__xpg_strerror_r, VALIDATED_CALL);
 	FUNC_MOCK_RCOUNTER_SET(core_log_default_function, VALIDATED_CALL);
+	FUNC_MOCK_RCOUNTER_SET(custom_log_function, VALIDATED_CALL);
 }
 
 void
diff --git a/src/test/core_log/core_log_common.h b/src/test/core_log/core_log_common.h
index b2f6909af27..c07c2384ef6 100644
--- a/src/test/core_log/core_log_common.h
+++ b/src/test/core_log/core_log_common.h
@@ -23,6 +23,7 @@
 #define VALIDATED_CALL 127
 #define NOT_CALLED VALIDATED_CALL
 #define CALLED (VALIDATED_CALL + 1)
+#define NOT_VALIDATED_CALL 0
 
 extern struct common_ctx {
 	bool use_last_error_msg;
@@ -49,6 +50,7 @@ FUNC_MOCK_EXTERN(last_error_msg_get);
 FUNC_MOCK_EXTERN(vsnprintf);
 FUNC_MOCK_EXTERN(__xpg_strerror_r);
 FUNC_MOCK_EXTERN(core_log_default_function);
+FUNC_MOCK_EXTERN(custom_log_function);
 
 /* helpers */
 
@@ -60,3 +62,6 @@ void test_strerror_r_fail_helper(bool before_glibc_2_13);
 
 void test_log_function_call_helper(enum core_log_level level,
 	bool call_log_function);
+
+void custom_log_function(enum core_log_level level, const char *file_name,
+	const int line_no, const char *function_name, const char *message);