diff --git a/tests/drivers/i2s/i2s_speed/src/main.c b/tests/drivers/i2s/i2s_speed/src/main.c
deleted file mode 100644
index c0ed0fe0c2a..00000000000
--- a/tests/drivers/i2s/i2s_speed/src/main.c
+++ /dev/null
@@ -1,14 +0,0 @@
-/*
- * Copyright (c) 2017 comsuisse AG
- *
- * SPDX-License-Identifier: Apache-2.0
- */
-
-
-#include <zephyr/kernel.h>
-#include <zephyr/ztest.h>
-
-extern void *test_i2s_speed_configure(void);
-extern void *test_i2s_speed_rxtx_configure(void);
-ZTEST_SUITE(drivers_i2s_speed, NULL, test_i2s_speed_configure, NULL, NULL, NULL);
-ZTEST_SUITE(drivers_i2s_speed_both_rxtx, NULL, test_i2s_speed_rxtx_configure, NULL, NULL, NULL);
diff --git a/tests/drivers/i2s/i2s_speed/src/test_i2s_speed.c b/tests/drivers/i2s/i2s_speed/src/test_i2s_speed.c
index f56b18b18f8..6bbbf00b153 100644
--- a/tests/drivers/i2s/i2s_speed/src/test_i2s_speed.c
+++ b/tests/drivers/i2s/i2s_speed/src/test_i2s_speed.c
@@ -496,7 +496,7 @@ ZTEST(drivers_i2s_speed_both_rxtx, test_i2s_dir_both_transfer_long)
 	zassert_equal(num_verified, NUM_BLOCKS, "Invalid RX blocks received");
 }
 
-void *test_i2s_speed_configure(void)
+static void *test_i2s_speed_configure(void)
 {
 	/* Configure I2S TX transfer. */
 	int ret;
@@ -519,7 +519,7 @@ void *test_i2s_speed_configure(void)
 	return 0;
 }
 
-void *test_i2s_speed_rxtx_configure(void)
+static void *test_i2s_speed_rxtx_configure(void)
 {
 	int ret;
 
@@ -545,3 +545,7 @@ void *test_i2s_speed_rxtx_configure(void)
 
 	return 0;
 }
+
+
+ZTEST_SUITE(drivers_i2s_speed, NULL, test_i2s_speed_configure, NULL, NULL, NULL);
+ZTEST_SUITE(drivers_i2s_speed_both_rxtx, NULL, test_i2s_speed_rxtx_configure, NULL, NULL, NULL);