diff --git a/src/flake8/style_guide.py b/src/flake8/style_guide.py
index 4626fd6..df6409c 100644
--- a/src/flake8/style_guide.py
+++ b/src/flake8/style_guide.py
@@ -429,7 +429,7 @@ class StyleGuideManager(object):
         :param dict diffinfo:
             Dictionary mapping filenames to sets of line number ranges.
         """
-        for guide in self.style_guides.values():
+        for guide in self.style_guides:
             guide.add_diff_ranges(diffinfo)