diff --git a/tests/test-c-strcasecmp.c b/tests/test-c-strcasecmp.c
index f7f6b43..47feac8 100644
--- a/tests/test-c-strcasecmp.c
+++ b/tests/test-c-strcasecmp.c
@@ -19,6 +19,7 @@
 #include <config.h>
 
 #include "c-strcase.h"
+#include "c-ctype.h"
 
 #include <locale.h>
 #include <string.h>
@@ -57,9 +58,11 @@ main (int argc, char *argv[])
   ASSERT (c_strcasecmp ("\303\266zg\303\274r", "\303\226ZG\303\234R") > 0); /* özgür */
   ASSERT (c_strcasecmp ("\303\226ZG\303\234R", "\303\266zg\303\274r") < 0); /* özgür */
 
+#if C_CTYPE_ASCII
   /* This test shows how strings of different size cannot compare equal.  */
   ASSERT (c_strcasecmp ("turkish", "TURK\304\260SH") < 0);
   ASSERT (c_strcasecmp ("TURK\304\260SH", "turkish") > 0);
+#endif
 
   return 0;
 }
diff --git a/tests/test-wcwidth.c b/tests/test-wcwidth.c
index 9fad785..fdbecc3 100644
--- a/tests/test-wcwidth.c
+++ b/tests/test-wcwidth.c
@@ -26,6 +26,7 @@ SIGNATURE_CHECK (wcwidth, int, (wchar_t));
 #include <locale.h>
 #include <string.h>
 
+#include "c-ctype.h"
 #include "localcharset.h"
 #include "macros.h"
 
@@ -34,9 +35,11 @@ main ()
 {
   wchar_t wc;
 
+#ifdef C_CTYPE_ASCII
   /* Test width of ASCII characters.  */
   for (wc = 0x20; wc < 0x7F; wc++)
     ASSERT (wcwidth (wc) == 1);
+#endif
 
   /* Switch to an UTF-8 locale.  */
   if (setlocale (LC_ALL, "fr_FR.UTF-8") != NULL