diff --git a/src/corelib/serialization/qxmlstream_p.h b/src/corelib/serialization/qxmlstream_p.h

index 4157fbbd..f8b1ede9 100644

--- a/src/corelib/serialization/qxmlstream_p.h

+++ b/src/corelib/serialization/qxmlstream_p.h

@@ -1250,7 +1250,7 @@ bool QXmlStreamReaderPrivate::parse()

             state_stack[tos] = 0;

             return true;

         } else if (act > 0) {

-            if (++tos == stack_size-1)

+            if (++tos >= stack_size-1)

                 reallocateStack();

             Value &val = sym_stack[tos];