diff --git a/bin/upload_to_s3.sh b/bin/upload_to_s3.sh
index 00b3a1d..4be74fa 100755
--- a/bin/upload_to_s3.sh
+++ b/bin/upload_to_s3.sh
@@ -7,7 +7,7 @@ else
   git clone git@github.com:cantino/selectorgadget.git tmp-sg
   cd tmp-sg
 fi
-s3cmd sync --cf-invalidate --guess-mime-type --no-mime-magic --delete-removed --rexclude=^.git\|^sites\|^test\|^bin . s3://selectorgadget.com/unstable/
-s3cmd put --cf-invalidate --guess-mime-type --no-mime-magic doc/* s3://selectorgadget.com
+s3cmd sync --no-check-md5 --cf-invalidate -M --no-mime-magic --delete-removed --rexclude=^.git\|^sites\|^test\|^bin . s3://selectorgadget.com/unstable/
+s3cmd put --no-check-md5 --cf-invalidate -M --no-mime-magic doc/* s3://selectorgadget.com
 git reset --hard && git clean -df && git checkout 0.4.2
-s3cmd sync --cf-invalidate --guess-mime-type --no-mime-magic --delete-removed --rexclude=^.git\|^sites\|^test\|^bin . s3://selectorgadget.com/stable/
+s3cmd sync --no-check-md5 --cf-invalidate -M --no-mime-magic --delete-removed --rexclude=^.git\|^sites\|^test\|^bin . s3://selectorgadget.com/stable/