diff --git a/Source/kwsys/kwsys_ios_sstream.h.in b/Source/kwsys/kwsys_ios_sstream.h.in
index 9b4ec6ba2..ccf9113a5 100644
--- a/Source/kwsys/kwsys_ios_sstream.h.in
+++ b/Source/kwsys/kwsys_ios_sstream.h.in
@@ -59,6 +59,7 @@
 
 namespace @KWSYS_NAMESPACE@_ios
 {
+using @KWSYS_NAMESPACE@_ios_namespace::streambuf;
 using @KWSYS_NAMESPACE@_ios_namespace::ostream;
 using @KWSYS_NAMESPACE@_ios_namespace::istream;
 using @KWSYS_NAMESPACE@_ios_namespace::istrstream;