diff --git a/Network/HTTP/Types.hs b/Network/HTTP/Types.hs
--- a/Network/HTTP/Types.hs
+++ b/Network/HTTP/Types.hs
@@ -49,6 +49,7 @@
 , Query
 , SimpleQueryItem
 , SimpleQuery
+, simpleQueryToQuery
 , renderQuery
 , renderSimpleQuery
 , parseQuery
@@ -247,6 +248,10 @@
 
 -- | Simplified Query type without support for parameter-less items.
 type SimpleQuery = [SimpleQueryItem]
+
+-- | Convert 'SimpleQuery' to 'Query'.
+simpleQueryToQuery :: SimpleQuery -> Query
+simpleQueryToQuery = map (\(a, b) -> (a, Just b))
 
 -- | Convert 'Query' to 'ByteString'.
 renderQuery :: Bool -- ^ prepend question mark?
diff --git a/http-types.cabal b/http-types.cabal
--- a/http-types.cabal
+++ b/http-types.cabal
@@ -7,7 +7,7 @@
 -- The package version. See the Haskell package versioning policy
 -- (http://www.haskell.org/haskellwiki/Package_versioning_policy) for
 -- standards guiding when and how versions should be incremented.
-Version:             0.4.0
+Version:             0.4.1
 
 -- A short (one-line) description of the package.
 Synopsis:            Generic HTTP types for Haskell (for both client and server code).