diff --git a/Source/kwsys/kwsys_ios_iostream.h.in b/Source/kwsys/kwsys_ios_iostream.h.in
index 2cc4b0678..115791c95 100644
--- a/Source/kwsys/kwsys_ios_iostream.h.in
+++ b/Source/kwsys/kwsys_ios_iostream.h.in
@@ -64,6 +64,8 @@
 #if !@KWSYS_NAMESPACE@_IOS_USE_SSTREAM
 namespace @KWSYS_NAMESPACE@_ios
 {
+  typedef int streamsize;
+  typedef int streamoff;
   using @KWSYS_NAMESPACE@_ios_namespace::ostream;
   using @KWSYS_NAMESPACE@_ios_namespace::istream;
   using @KWSYS_NAMESPACE@_ios_namespace::ios;