diff --git a/include/close_code.h b/include/close_code.h
index b3b70a4c8..f1fea37d1 100644
--- a/include/close_code.h
+++ b/include/close_code.h
@@ -26,6 +26,9 @@
  *  after you finish any function and structure declarations in your headers
  */
 
+#ifndef _begin_code_h
+#error close_code.h included without matching begin_code.h
+#endif
 #undef _begin_code_h
 
 /* Reset structure packing at previous byte alignment */