diff -r d19877568878 -r 62c6d883f753 lib/iec_std_lib.h
--- a/lib/iec_std_lib.h	Fri Nov 09 14:34:36 2012 +0000
+++ b/lib/iec_std_lib.h	Mon Nov 12 22:26:21 2012 +0100
@@ -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 */