diff --git a/yesod/hsfiles/mongo.hsfiles b/yesod/hsfiles/mongo.hsfiles
index 48005d0a..fb22b601 100644
--- a/yesod/hsfiles/mongo.hsfiles
+++ b/yesod/hsfiles/mongo.hsfiles
@@ -170,7 +170,13 @@ instance Yesod App where
     -- and names them based on a hash of their content. This allows
     -- expiration dates to be set far in the future without worry of
     -- users receiving stale content.
-    addStaticContent = addStaticContentExternal minifym base64md5 Settings.staticDir (StaticR . flip StaticRoute [])
+    addStaticContent =
+        addStaticContentExternal minifym genFileName Settings.staticDir (StaticR . flip StaticRoute [])
+      where
+        -- Generate a unique filename based on the content itself
+        genFileName lbs
+            | development = "autogen-" ++ base64md5 lbs
+            | otherwise   = base64md5 lbs
 
     -- Place Javascript at bottom of the body tag so the rest of the page loads first
     jsLoader _ = BottomOfBody
diff --git a/yesod/hsfiles/mysql.hsfiles b/yesod/hsfiles/mysql.hsfiles
index d3a0fb33..4a3d9d62 100644
--- a/yesod/hsfiles/mysql.hsfiles
+++ b/yesod/hsfiles/mysql.hsfiles
@@ -172,7 +172,13 @@ instance Yesod App where
     -- and names them based on a hash of their content. This allows
     -- expiration dates to be set far in the future without worry of
     -- users receiving stale content.
-    addStaticContent = addStaticContentExternal minifym base64md5 Settings.staticDir (StaticR . flip StaticRoute [])
+    addStaticContent =
+        addStaticContentExternal minifym genFileName Settings.staticDir (StaticR . flip StaticRoute [])
+      where
+        -- Generate a unique filename based on the content itself
+        genFileName lbs
+            | development = "autogen-" ++ base64md5 lbs
+            | otherwise   = base64md5 lbs
 
     -- Place Javascript at bottom of the body tag so the rest of the page loads first
     jsLoader _ = BottomOfBody
diff --git a/yesod/hsfiles/postgres.hsfiles b/yesod/hsfiles/postgres.hsfiles
index 86cba297..1eef35ff 100644
--- a/yesod/hsfiles/postgres.hsfiles
+++ b/yesod/hsfiles/postgres.hsfiles
@@ -172,7 +172,13 @@ instance Yesod App where
     -- and names them based on a hash of their content. This allows
     -- expiration dates to be set far in the future without worry of
     -- users receiving stale content.
-    addStaticContent = addStaticContentExternal minifym base64md5 Settings.staticDir (StaticR . flip StaticRoute [])
+    addStaticContent =
+        addStaticContentExternal minifym genFileName Settings.staticDir (StaticR . flip StaticRoute [])
+      where
+        -- Generate a unique filename based on the content itself
+        genFileName lbs
+            | development = "autogen-" ++ base64md5 lbs
+            | otherwise   = base64md5 lbs
 
     -- Place Javascript at bottom of the body tag so the rest of the page loads first
     jsLoader _ = BottomOfBody
diff --git a/yesod/hsfiles/simple.hsfiles b/yesod/hsfiles/simple.hsfiles
index 4659b819..d2abbe12 100644
--- a/yesod/hsfiles/simple.hsfiles
+++ b/yesod/hsfiles/simple.hsfiles
@@ -152,7 +152,13 @@ instance Yesod App where
     -- and names them based on a hash of their content. This allows
     -- expiration dates to be set far in the future without worry of
     -- users receiving stale content.
-    addStaticContent = addStaticContentExternal minifym base64md5 Settings.staticDir (StaticR . flip StaticRoute [])
+    addStaticContent =
+        addStaticContentExternal minifym genFileName Settings.staticDir (StaticR . flip StaticRoute [])
+      where
+        -- Generate a unique filename based on the content itself
+        genFileName lbs
+            | development = "autogen-" ++ base64md5 lbs
+            | otherwise   = base64md5 lbs
 
     -- Place Javascript at bottom of the body tag so the rest of the page loads first
     jsLoader _ = BottomOfBody
diff --git a/yesod/hsfiles/sqlite.hsfiles b/yesod/hsfiles/sqlite.hsfiles
index c7c58eeb..5feb86b1 100644
--- a/yesod/hsfiles/sqlite.hsfiles
+++ b/yesod/hsfiles/sqlite.hsfiles
@@ -172,7 +172,13 @@ instance Yesod App where
     -- and names them based on a hash of their content. This allows
     -- expiration dates to be set far in the future without worry of
     -- users receiving stale content.
-    addStaticContent = addStaticContentExternal minifym base64md5 Settings.staticDir (StaticR . flip StaticRoute [])
+    addStaticContent =
+        addStaticContentExternal minifym genFileName Settings.staticDir (StaticR . flip StaticRoute [])
+      where
+        -- Generate a unique filename based on the content itself
+        genFileName lbs
+            | development = "autogen-" ++ base64md5 lbs
+            | otherwise   = base64md5 lbs
 
     -- Place Javascript at bottom of the body tag so the rest of the page loads first
     jsLoader _ = BottomOfBody