diff --git a/libstdc++-v3/config/bsd/bits/ctype_specializations.h b/libstdc++-v3/config/bsd/bits/ctype_specializations.h
index c156a5a2a2d8..c2a49c4025df 100644
--- a/libstdc++-v3/config/bsd/bits/ctype_specializations.h
+++ b/libstdc++-v3/config/bsd/bits/ctype_specializations.h
@@ -41,7 +41,7 @@
     if (__m & digit || __m & xdigit)
       return __isctype(__c, __m);
     else
-      return __istype(__c);
+      return __istype(__c, __m);
   }
 
   const char*