diff --git a/src/common/chartype.h b/src/common/chartype.h
index a1cdfc56d..72ccf7560 100644
--- a/src/common/chartype.h
+++ b/src/common/chartype.h
@@ -38,6 +38,12 @@
 
 
 
+#include <ctype.h>
+
+/* common */
+#include "inline.h"
+
+
 /* This module contains replacements for functions in ctype.h besides other
  * functions. There is a problem with using ctype.h directly:
  * The parameter must have a value of "unsigned char" or EOF.
@@ -67,6 +73,16 @@ int IsAscii (char C);
 int IsBlank (char C);
 /* Check for a space or tab */
 
+#if defined(HAVE_INLINE)
+INLINE int IsControl (char C)
+/* Check for control chars */
+{
+    return iscntrl ((unsigned char) C);
+}
+#else
+#  define IsControl(C) 	       	iscntrl (C)
+#endif
+
 int IsSpace (char C);
 /* Check for any white space characters */