diff --git a/tests/streams/bstream.h b/tests/streams/bstream.h
index 3f5e1f1d59..9b46aa90c8 100644
--- a/tests/streams/bstream.h
+++ b/tests/streams/bstream.h
@@ -375,7 +375,7 @@ protected:
             const char *buf = "1234567890";
             (void)stream_out.Write(buf, 10);
 
-            off_t pos = stream_out.SeekO(5, wxFromStart);
+            wxFileOffset pos = stream_out.SeekO(5, wxFromStart);
             CPPUNIT_ASSERT_EQUAL(pos, stream_out.TellO());
             (void)stream_out.PutC('1');
             CPPUNIT_ASSERT_EQUAL(6, stream_out.TellO());