@@ -13,11 +13,14 @@
  * Public License, either version 2 or 3, which can be found in the file
  * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
  * file.
  */
 
-#import "macros.h"
+#ifndef OBJFW_BLOCK_H
+#define OBJFW_BLOCK_H
+
+#include "macros.h"
 
 OF_ASSUME_NONNULL_BEGIN
 
 typedef struct of_block_literal_t {
 #ifdef __OBJC__
@@ -68,5 +71,7 @@
 #ifndef Block_release
 # define Block_release(...) _Block_release((const void *)(__VA_ARGS__))
 #endif
 
 OF_ASSUME_NONNULL_END
+
+#endif