diff --git a/tests/unit/base64/main.c b/tests/unit/base64/main.c
index 0b39e68ade4..51eb6332645 100644
--- a/tests/unit/base64/main.c
+++ b/tests/unit/base64/main.c
@@ -60,7 +60,7 @@ static const unsigned char base64_test_enc5[] =
 	"JEhuVodiWr2/F9mixBcaAZTtjx4Rs9cJDLbpEG8i\n\r\ni"
 	"swcFdsn6MWwINP+Nwmw4AEPpVJevUEvRQbqVMVoLlw= ";
 
-static void test_base64_codec(void)
+ZTEST(lib_base64, test_base64_codec)
 {
 	size_t len;
 	int rc;
@@ -129,10 +129,4 @@ static void test_base64_codec(void)
 	zassert_equal(rc, -ENOMEM, "Error: dst NULL: decode test return value");
 }
 
-void test_main(void)
-{
-	ztest_test_suite(lib_base64_test,
-			 ztest_unit_test(test_base64_codec));
-
-	ztest_run_test_suite(lib_base64_test);
-}
+ZTEST_SUITE(lib_base64, NULL, NULL, NULL, NULL, NULL);
diff --git a/tests/unit/base64/prj.conf b/tests/unit/base64/prj.conf
new file mode 100644
index 00000000000..963087265ce
--- /dev/null
+++ b/tests/unit/base64/prj.conf
@@ -0,0 +1 @@
+CONFIG_ZTEST_NEW_API=y