diff --git a/src/rp2_common/hardware_hazard3/include/hardware/hazard3/features.h b/src/rp2_common/hardware_hazard3/include/hardware/hazard3/features.h
index 146b13f97..25e5d2fba 100644
--- a/src/rp2_common/hardware_hazard3/include/hardware/hazard3/features.h
+++ b/src/rp2_common/hardware_hazard3/include/hardware/hazard3/features.h
@@ -4,8 +4,8 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
-#ifndef _HARDWARE_HAZARD3_FEATURES_
-#define _HARDWARE_HAZARD3_FEATURES_
+#ifndef _HARDWARE_HAZARD3_FEATURES_H
+#define _HARDWARE_HAZARD3_FEATURES_H
 
 #include "pico.h"