diff --git a/pypreprocessor/__init__.py b/pypreprocessor/__init__.py
index b0b2a07..8a02639 100644
--- a/pypreprocessor/__init__.py
+++ b/pypreprocessor/__init__.py
@@ -100,7 +100,9 @@ def __if(self):
 
     # evaluate
     def lexer(self, line):
-    # return values are (squelch, metadata)
+        # strip any and all leading whitespace characters
+        line = line.lstrip()
+        # return values are (squelch, metadata)
         if not (self.__ifblocks or self.__excludeblock):
             if 'pypreprocessor.parse()' in line:
                 return True, True