diff --git a/Changelog.md b/Changelog.md
--- a/Changelog.md
+++ b/Changelog.md
@@ -2,6 +2,10 @@
 
 ## Unreleased changes
 
+## v0.2.2.3
+- Don't camel-case message names.  This reverts behavior which was added
+  in v0.2.2.0.
+
 ## v0.2.2.2
 - Bump the dependency for `process-1.6`.
 
diff --git a/proto-lens-protoc.cabal b/proto-lens-protoc.cabal
--- a/proto-lens-protoc.cabal
+++ b/proto-lens-protoc.cabal
@@ -1,5 +1,5 @@
 name:                proto-lens-protoc
-version:             0.2.2.2
+version:             0.2.2.3
 synopsis:            Protocol buffer compiler for the proto-lens library.
 description:
   Turn protocol buffer files (.proto) into Haskell files (.hs) which
diff --git a/src/Data/ProtoLens/Compiler/Definitions.hs b/src/Data/ProtoLens/Compiler/Definitions.hs
--- a/src/Data/ProtoLens/Compiler/Definitions.hs
+++ b/src/Data/ProtoLens/Compiler/Definitions.hs
@@ -252,10 +252,10 @@
     -- Make a name that doesn't overlap with those already defined by submessages
     -- or subenums.
     hsNameUnique ns n
-        | n' `elem` ns = n' <> "'"
+        | n' `elem` ns = n' ++ "'"
         | otherwise = n'
       where
-        n' = hsName n
+        n' = hsName $ camelCase n
     -- The Haskell "type" namespace
     subdefTypes = Set.fromList $ map hsName
                     $ toListOf (nestedType . traverse . name) d
@@ -275,7 +275,7 @@
     . fmap (\f -> (f ^. maybe'oneofIndex, [f]))
 
 hsName :: Text -> String
-hsName = unpack . capitalize . camelCase
+hsName = unpack . capitalize
 
 mkFieldName :: String -> Text -> FieldName
 mkFieldName hsPrefix n = FieldName