diff --git a/hal/tests/UNITTESTS/doubles/gpio_object.h b/hal/tests/UNITTESTS/doubles/gpio_object.h
index 9f31aeb9b3..2fd544a855 100644
--- a/hal/tests/UNITTESTS/doubles/gpio_object.h
+++ b/hal/tests/UNITTESTS/doubles/gpio_object.h
@@ -27,7 +27,7 @@ extern "C" {
 #endif
 
 typedef struct {
-   int unused;
+    int unused;
 } gpio_t;
 
 #ifdef __cplusplus