diff --git a/src/runtime/python/examples/gf_utils.py b/src/runtime/python/examples/gf_utils.py
index d6d3421ac..b097cb118 100644
--- a/src/runtime/python/examples/gf_utils.py
+++ b/src/runtime/python/examples/gf_utils.py
@@ -154,7 +154,7 @@ def pgf_parse(args):
     import translation_pipeline;
 
     preprocessor = lexer();
-    inputSet = translation_pipeline.web_lexer(grammar, args.srclang, preprocessor(args.inputstream) );
+    inputSet = translation_pipeline.web_lexer(grammar, args.srclang, imap(preprocessor, args.inputstream) );
     outputPrinter = lambda X: "%f\t%s" %(X[0], str(X[1])); #operator.itemgetter(1);
     callbacks = [('PN', translation_pipeline.parseNames(grammar, args.srclang)), ('Symb', translation_pipeline.parseUnknown(grammar, args.srclang))];
     parser = getKBestParses(grammar, args.srclang, 1, callbacks);
@@ -170,7 +170,7 @@ def pgf_kparse(args):
     import translation_pipeline;
     
     preprocessor = lexer();
-    inputSet = translation_pipeline.web_lexer(grammar, args.srclang, preprocessor(args.inputstream) );
+    inputSet = translation_pipeline.web_lexer(grammar, args.srclang, imap(preprocessor, args.inputstream) );
     outputPrinter = printJohnsonRerankerFormat;
     callbacks = [('PN', translation_pipeline.parseNames(grammar, args.srclang)), ('Symb', translation_pipeline.parseUnknown(grammar, args.srclang))];
     parser = getKBestParses(grammar, args.srclang, args.K, callbacks=callbacks);