diff --git a/servant-purescript.cabal b/servant-purescript.cabal
--- a/servant-purescript.cabal
+++ b/servant-purescript.cabal
@@ -1,5 +1,5 @@
 name:                servant-purescript
-version:             0.4.0.0
+version:             0.4.0.1
 synopsis:            Generate PureScript accessor functions for you servant API
 description:         Please see README.md
 homepage:            https://github.com/eskimor/servant-purescript#readme
diff --git a/src/Servant/PureScript/CodeGen.hs b/src/Servant/PureScript/CodeGen.hs
--- a/src/Servant/PureScript/CodeGen.hs
+++ b/src/Servant/PureScript/CodeGen.hs
@@ -146,9 +146,9 @@
 
 genBuildQueryArg :: QueryArg PSType -> Doc
 genBuildQueryArg arg = case arg ^. queryArgType of
-    Normal -> genQueryEncoding "encodeQuery"
-    Flag   -> genQueryEncoding "encodeQuery"
-    List   -> genQueryEncoding "encodeListQuery"
+    Normal -> genQueryEncoding "encodeQueryItem spOpts_'"
+    Flag   -> genQueryEncoding "encodeQueryItem spOpts_'"
+    List   -> genQueryEncoding "encodeListQuery spOpts_'"
   where
     argText = arg ^. queryArgName ^. argName ^. to unPathSegment
     encodedArgName = strictText . textURLEncode True $ argText