diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index eadf65b3f665..8c5da550a8ca 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,8 @@
+2010-10-13  Jonathan Wakely  <jwakely.gcc@gmail.com>
+
+	PR libstdc++/45990
+	* include/bits/regex.h (regex_traits::isctype): DR 1337.
+
 2010-10-13  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	* include/bits/random.h (discrete_distribution<>::param_type::
diff --git a/libstdc++-v3/include/bits/regex.h b/libstdc++-v3/include/bits/regex.h
index bbec88cb7ffd..64d4407fd721 100644
--- a/libstdc++-v3/include/bits/regex.h
+++ b/libstdc++-v3/include/bits/regex.h
@@ -287,7 +287,7 @@ namespace std
       const ctype<_Ch_type>& __ctype(use_facet<
 				     ctype<_Ch_type> >(_M_locale));
       
-      if (__ctype.is(__c, __f))
+      if (__ctype.is(__f, __c))
 	return true;
       
       // special case of underscore in [[:w:]]