--- a/lib/iec_std_lib.h	Thu Nov 22 18:53:37 2012 +0000
+++ b/lib/iec_std_lib.h	Thu Nov 22 19:02:05 2012 +0000
@@ -26,6 +26,10 @@
  *       $gcc -E iec_std_lib.h 
  */
 
+#ifndef _IEC_STD_LIB_H
+#define _IEC_STD_LIB_H
+
+
 #include <limits.h>
 #include <float.h>
 #include <math.h>
@@ -2157,3 +2161,5 @@
 /********************************************/
 
 /* Do we support this? */
+
+#endif /* _IEC_STD_LIB_H */