diff --git a/kwsys_ios_sstream.h.in b/kwsys_ios_sstream.h.in
index 2cbbe7624d9002bd2efde861c7332fb8718c70f5..2c3a99a5592c3b2c2319ec4bdd9c4b4166da2462 100644
--- a/kwsys_ios_sstream.h.in
+++ b/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;