diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9f92b46d0..f53e13eb1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 ### Added
 - Option to specify nulls first or last, eg `/people?order=age.desc.nullsfirst`
 - Filter nulls, `?col=is.null` and `?col=isnot.null`
+### Fixed
+- Allow NULL values in posts
 
 ## [0.2.7.0] - 2015-03-03
 ### Added
diff --git a/src/App.hs b/src/App.hs
index f0c09a11b..00b3b3cf5 100644
--- a/src/App.hs
+++ b/src/App.hs
@@ -112,7 +112,7 @@ app v1schema reqBody req =
             then inserted
             else filterWithKey (const . (`elem` primaryKeys)) inserted
         let params = urlEncodeVars
-              $ map (\t -> (cs $ fst t, "eq." <> cs (unquoted $ snd t)))
+              $ map (\t -> (cs $ fst t, cs (paramFilter $ snd t)))
               $ sortBy (comparing fst) $ toList primaries
         return $ responseLBS status201
           [ jsonH
diff --git a/src/PgQuery.hs b/src/PgQuery.hs
index 38a230156..9526cd24b 100644
--- a/src/PgQuery.hs
+++ b/src/PgQuery.hs
@@ -115,7 +115,7 @@ insertInto t cols vals = B.Stmt
   ("insert into " <> fromQt t <> " (" <>
     T.intercalate ", " (map pgFmtIdent cols) <>
     ") values ("
-    <> T.intercalate ", " (map ((<> "::unknown") . pgFmtLit . unquoted) vals)
+    <> T.intercalate ", " (map insertableValue vals)
     <> ") returning row_to_json(" <> fromQt t <> ".*)")
   empty True
 
@@ -126,7 +126,7 @@ insertSelect t cols vals = B.Stmt
   ("insert into " <> fromQt t <> " ("
     <> T.intercalate ", " (map pgFmtIdent cols)
     <> ") select "
-    <> T.intercalate ", " (map ((<> "::unknown") . pgFmtLit . unquoted) vals))
+    <> T.intercalate ", " (map insertableValue vals))
   empty True
 
 update :: QualifiedTable -> [T.Text] -> [JSON.Value] -> PStmt
@@ -134,7 +134,7 @@ update t cols vals = B.Stmt
   ("update " <> fromQt t <> " set ("
     <> T.intercalate ", " (map pgFmtIdent cols)
     <> ") = ("
-    <> T.intercalate ", " (map ((<> "::unknown") . pgFmtLit . unquoted) vals)
+    <> T.intercalate ", " (map insertableValue vals)
     <> ")")
   empty True
 
@@ -233,3 +233,11 @@ unquoted (JSON.Number n) =
   cs $ formatScientific Fixed (if isInteger n then Just 0 else Nothing) n
 unquoted (JSON.Bool b) = cs . show $ b
 unquoted _ = ""
+
+insertableValue :: JSON.Value -> T.Text
+insertableValue JSON.Null = "null"
+insertableValue v = ((<> "::unknown") . pgFmtLit . unquoted) v
+
+paramFilter :: JSON.Value -> T.Text
+paramFilter JSON.Null = "is.null"
+paramFilter v = "eq." <> unquoted v
diff --git a/test/Feature/InsertSpec.hs b/test/Feature/InsertSpec.hs
index d593421cb..3117791ed 100644
--- a/test/Feature/InsertSpec.hs
+++ b/test/Feature/InsertSpec.hs
@@ -66,6 +66,15 @@ spec = afterAll_ resetDb $ around withApp $ do
             simpleHeaders p `shouldSatisfy` matchHeader hLocation "/no_pk\\?a=eq.bar&b=eq.baz"
             simpleStatus p `shouldBe` created201
 
+        it "can post nulls" $ do
+          p <- request methodPost "/no_pk"
+                       [("Prefer", "return=representation")]
+                       [json| { "a":null, "b":"foo" } |]
+          liftIO $ do
+            simpleBody p `shouldBe` [json| { "a":null, "b":"foo" } |]
+            simpleHeaders p `shouldSatisfy` matchHeader hLocation "/no_pk\\?a=is.null&b=eq.foo"
+            simpleStatus p `shouldBe` created201
+
     context "with compound pk supplied" . after_ (clearTable "compound_pk") $
       it "builds response location header appropriately" $
         post "/compound_pk" [json| { "k1":12, "k2":42 } |]