diff --git a/preprocessor.py b/preprocessor.py
index f5bc08637..b9165e60e 100644
--- a/preprocessor.py
+++ b/preprocessor.py
@@ -66,7 +66,7 @@ def setup_processor():
 def main():
     processor = setup_processor()
     processor.preprocess()
-    processor.update_globals
+    processor.update_globals()
 
 # only run against stdin when not included as a module
 if __name__ == "__main__":