diff --git a/servant-serf.cabal b/servant-serf.cabal
--- a/servant-serf.cabal
+++ b/servant-serf.cabal
@@ -1,7 +1,7 @@
 cabal-version: 2.0
 
 name: servant-serf
-version: 0.3.1.0
+version: 0.3.1.1
 synopsis: Automatically generate Servant API modules.
 description:
   = servant-serf
diff --git a/source/library/ServantSerf/Module.hs b/source/library/ServantSerf/Module.hs
--- a/source/library/ServantSerf/Module.hs
+++ b/source/library/ServantSerf/Module.hs
@@ -20,8 +20,9 @@
           . ModuleName.fromFilePath
           $ Context.source context
       Just x -> ModuleName.toString x
+    suffix = Config.excludeSuffix config
     moduleNames =
-      filter (not . List.isSuffixOf (Config.excludeSuffix config))
+      (if null suffix then id else filter $ not . List.isSuffixOf suffix)
         . fmap ModuleName.toString
         . List.sort
         . Maybe.mapMaybe ModuleName.fromFilePath