diff --git a/src/PostgREST/Request/ApiRequest.hs b/src/PostgREST/Request/ApiRequest.hs
index 7fcbf60b9..e67b5689d 100644
--- a/src/PostgREST/Request/ApiRequest.hs
+++ b/src/PostgREST/Request/ApiRequest.hs
@@ -243,9 +243,9 @@ userApiRequest conf@AppConfig{..} dbStructure req reqBody
   parsedColumns = pRequestColumns columns
   payloadColumns =
     case (contentType, action) of
-      (_, ActionInvoke InvGet)                         -> S.fromList $ fst <$> rpcQParams
-      (_, ActionInvoke InvHead)                        -> S.fromList $ fst <$> rpcQParams
-      (CTOther "application/x-www-form-urlencoded", _) -> S.fromList $ map (toS . fst) $ parseSimpleQuery $ toS reqBody
+      (_, ActionInvoke InvGet)  -> S.fromList $ fst <$> rpcQParams
+      (_, ActionInvoke InvHead) -> S.fromList $ fst <$> rpcQParams
+      (CTUrlEncoded, _)         -> S.fromList $ map (toS . fst) $ parseSimpleQuery $ toS reqBody
       _ -> case (relevantPayload, fromRight Nothing parsedColumns) of
         (Just ProcessedJSON{pjKeys}, _) -> pjKeys
         (Just RawJSON{}, Just cls)      -> cls
diff --git a/test/Feature/RpcSpec.hs b/test/Feature/RpcSpec.hs
index 893559c86..6b9481401 100644
--- a/test/Feature/RpcSpec.hs
+++ b/test/Feature/RpcSpec.hs
@@ -659,6 +659,34 @@ spec actualPgVersion =
       it "overloaded(text, text, text)" $
         get "/rpc/overloaded?a=1&b=2&c=3" `shouldRespondWith` [json|"123"|]
 
+      it "overloaded_html_form()" $
+        request methodPost "/rpc/overloaded_html_form"
+            [("Content-Type", "application/x-www-form-urlencoded")]
+            ""
+          `shouldRespondWith`
+            [json|[1,2,3]|]
+
+      it "overloaded_html_form(json) single-object" $
+        request methodPost "/rpc/overloaded_html_form"
+            [("Content-Type", "application/x-www-form-urlencoded"), ("Prefer","params=single-object")]
+            "a=1&b=2&c=3"
+          `shouldRespondWith`
+            [json|{"a": "1", "b": "2", "c": "3"}|]
+
+      it "overloaded_html_form(int, int)" $
+        request methodPost "/rpc/overloaded_html_form"
+            [("Content-Type", "application/x-www-form-urlencoded")]
+            "a=1&b=2"
+          `shouldRespondWith`
+            [str|3|]
+
+      it "overloaded_html_form(text, text, text)" $
+        request methodPost "/rpc/overloaded_html_form"
+            [("Content-Type", "application/x-www-form-urlencoded")]
+            "a=1&b=2&c=3"
+          `shouldRespondWith`
+            [json|"123"|]
+
     context "only for POST rpc" $ do
       it "gives a parse filter error if GET style proc args are specified" $
         post "/rpc/sayhello?name=John" [json|{}|] `shouldRespondWith` 400
diff --git a/test/fixtures/schema.sql b/test/fixtures/schema.sql
index 6099cbf74..0d4ca85d4 100644
--- a/test/fixtures/schema.sql
+++ b/test/fixtures/schema.sql
@@ -1267,6 +1267,22 @@ create or replace function test.overloaded(a text, b text, c text) returns text
   select a || b || c
 $$ language sql;
 
+create or replace function test.overloaded_html_form() returns setof int as $$
+values (1), (2), (3);
+$$ language sql;
+
+create or replace function test.overloaded_html_form(single_param json) returns json as $$
+select single_param;
+$$ language sql;
+
+create or replace function test.overloaded_html_form(a int, b int) returns int as $$
+select a + b
+$$ language sql;
+
+create or replace function test.overloaded_html_form(a text, b text, c text) returns text as $$
+select a || b || c
+$$ language sql;
+
 create table test.leak(
   id serial primary key,
   blob bytea