diff --git a/libraries/mbed/api/mbed_assert.h b/libraries/mbed/api/mbed_assert.h
index 5e205d023f..de74992e14 100644
--- a/libraries/mbed/api/mbed_assert.h
+++ b/libraries/mbed/api/mbed_assert.h
@@ -1,5 +1,5 @@
-#ifndef ASSERT_H
-#define ASSERT_H
+#ifndef MBED_ASSERT_H
+#define MBED_ASSERT_H
 
 #ifdef __cplusplus
 extern "C" {