diff --git a/CONTRIBUTORS.txt b/CONTRIBUTORS.txt
index e57d3b0..b30a438 100644
--- a/CONTRIBUTORS.txt
+++ b/CONTRIBUTORS.txt
@@ -3,4 +3,5 @@ Project created by Tarek Ziadé.
 Contributors:
 
 - Tamás Gulácsi
+- Nicolas Dumazet
 
diff --git a/flake8/run.py b/flake8/run.py
index c217324..13b0746 100644
--- a/flake8/run.py
+++ b/flake8/run.py
@@ -54,8 +54,12 @@ def main():
 
 
 def _get_files(repo, **kwargs):
+    seen = set()
     for rev in xrange(repo[kwargs['node']], len(repo)):
         for file_ in repo[rev].files():
+            if file_ in seen:
+                continue
+            seen.add(file_)
             if not file_.endswith('.py'):
                 continue
             if skip_file(file_):
@@ -82,11 +86,9 @@ def hg_hook(ui, repo, **kwargs):
     for file_ in _get_files(repo, **kwargs):
         warnings += check_file(file_)
 
-    strict = ui.config('flake8', 'strict')
-    if strict is None:
-        strict = True
+    strict = ui.configbool('flake8', 'strict', default=True)
 
-    if strict.lower() in ('1', 'true'):
+    if strict:
         return warnings
 
     return 0