diff --git a/tests/drivers/pwm/pwm_api/src/main.c b/tests/drivers/pwm/pwm_api/src/main.c
index 94a8dd88556..20269584a0d 100644
--- a/tests/drivers/pwm/pwm_api/src/main.c
+++ b/tests/drivers/pwm/pwm_api/src/main.c
@@ -14,13 +14,15 @@
 #include <zephyr.h>
 #include <ztest.h>
 
-extern void test_pwm_usec(void);
-extern void test_pwm_cycle(void);
+void test_pwm_usec(void);
+void test_pwm_cycle(void);
+void test_pwm_nsec(void);
 
 void test_main(void)
 {
 	ztest_test_suite(pwm_basic_test,
 			 ztest_unit_test(test_pwm_usec),
+			 ztest_unit_test(test_pwm_nsec),
 			 ztest_unit_test(test_pwm_cycle));
 	ztest_run_test_suite(pwm_basic_test);
 }