diff --git a/ProxyStubGenerator/StubGenerator.py b/ProxyStubGenerator/StubGenerator.py
index 356ec0f..92aafe3 100755
--- a/ProxyStubGenerator/StubGenerator.py
+++ b/ProxyStubGenerator/StubGenerator.py
@@ -1773,7 +1773,7 @@ def EmitStub(interface_name, methods, stub_methods_name, interface, prepared_par
         #
 
         def EmitCompleteMethod():
-            emit.Line("uint32_t _Complete(RPC::Data::Frame::Reader& %s)" %  vars["reader"])
+            emit.Line("uint32_t _Complete(RPC::Data::Frame::Reader& %s) const" %  vars["reader"])
             emit.Line("{")
             emit.IndentInc()
             emit.Line("uint32_t result = Core::ERROR_NONE;")