diff --git a/src/zipios++/filterinputstreambuf.cpp b/src/zipios++/filterinputstreambuf.cpp
index 4137973a1e..a0212ee5e8 100644
--- a/src/zipios++/filterinputstreambuf.cpp
+++ b/src/zipios++/filterinputstreambuf.cpp
@@ -9,6 +9,7 @@ FilterInputStreambuf::FilterInputStreambuf( streambuf *inbuf, bool del_inbuf )
   : _inbuf( inbuf),
     _del_inbuf( del_inbuf )
 {
+  _s_pos = 0;
   if ( _inbuf == NULL ) {
     // throw an exception
   }