--- generic/tixGrUtl.c.orig
+++ generic/tixGrUtl.c
@@ -17,6 +17,7 @@
 #include <tixInt.h>
 #include <tixDef.h>
 #include <tixGrid.h>
+#include <ctype.h>
 
 #ifndef UCHAR
 #define UCHAR(c) ((unsigned char) (c))
--- generic/tixImgXpm.c.orig
+++ generic/tixImgXpm.c
@@ -16,6 +16,7 @@
 #include <tixPort.h>
 #include <tixInt.h>
 #include <tixImgXpm.h>
+#include <ctype.h>
 
 /*
  * Prototypes for procedures used only locally in this file: