diff --git a/CHANGELOG.md b/CHANGELOG.md
index 88b258b79..6c0dfdbad 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Fixed
 
+- #1113, Fix UPSERT failing when having a camel case PK column - @steve-chavez
+
 ### Changed
 
 ## [0.5.0.0] - 2018-05-14
diff --git a/src/PostgREST/QueryBuilder.hs b/src/PostgREST/QueryBuilder.hs
index 5a8522a49..4d1491df0 100644
--- a/src/PostgREST/QueryBuilder.hs
+++ b/src/PostgREST/QueryBuilder.hs
@@ -288,7 +288,7 @@ requestToQuery schema _ (DbMutate (Insert mainTbl pkCols p@(PayloadJSON _ pType
         -- Only used for PUT
         ("WHERE " <> intercalate " AND " (pgFmtLogicTree (QualifiedIdentifier "" "_") <$> logicForest)) `emptyOnFalse` null logicForest],
     maybe "" (\x -> (
-      "ON CONFLICT(" <> intercalate ", " pkCols <> ") " <> case x of
+      "ON CONFLICT(" <> intercalate ", " (pgFmtIdent <$> pkCols) <> ") " <> case x of
       IgnoreDuplicates ->
         "DO NOTHING"
       MergeDuplicates  ->
diff --git a/test/Feature/UpsertSpec.hs b/test/Feature/UpsertSpec.hs
index 3c52b9696..e7cbcb177 100644
--- a/test/Feature/UpsertSpec.hs
+++ b/test/Feature/UpsertSpec.hs
@@ -198,3 +198,30 @@ spec =
           [("Prefer", "return=representation"), ("Accept", "application/vnd.pgrst.object+json")]
           [str| [ { "name": "Ruby", "rank": 11 } ]|]
           `shouldRespondWith` [json|{ "name": "Ruby", "rank": 11 }|] { matchHeaders = [matchContentTypeSingular] }
+
+    context "with a camel case pk column" $ do
+      it "works with POST and merge-duplicates/ignore-duplicates headers" $ do
+        request methodPost "/UnitTest" [("Prefer", "return=representation"), ("Prefer", "resolution=merge-duplicates")]
+          [json| [
+            { "idUnitTest": 1, "nameUnitTest": "name of unittest 1" },
+            { "idUnitTest": 2, "nameUnitTest": "name of unittest 2" }
+          ]|] `shouldRespondWith` [json|[
+            { "idUnitTest": 1, "nameUnitTest": "name of unittest 1" },
+            { "idUnitTest": 2, "nameUnitTest": "name of unittest 2" }
+          ]|]
+          { matchStatus = 201
+          , matchHeaders = ["Preference-Applied" <:> "resolution=merge-duplicates", matchContentTypeJson]
+          }
+        request methodPost "/UnitTest" [("Prefer", "return=representation"), ("Prefer", "resolution=ignore-duplicates")]
+          [json| [
+            { "idUnitTest": 1, "nameUnitTest": "name of unittest 1" },
+            { "idUnitTest": 2, "nameUnitTest": "name of unittest 2" }
+          ]|] `shouldRespondWith` [json|[]|]
+          { matchStatus = 201
+          , matchHeaders = ["Preference-Applied" <:> "resolution=ignore-duplicates", matchContentTypeJson]
+          }
+
+      it "works with PUT" $ do
+        put "/UnitTest?idUnitTest=eq.1" [str| [ { "idUnitTest": 1, "nameUnitTest": "unit test 1" } ]|] `shouldRespondWith` 204
+        get "/UnitTest?idUnitTest=eq.1" `shouldRespondWith`
+          [json| [ { "idUnitTest": 1, "nameUnitTest": "unit test 1" } ]|] { matchHeaders = [matchContentTypeJson] }
diff --git a/test/fixtures/data.sql b/test/fixtures/data.sql
index d421b4d0a..b8d9e6436 100644
--- a/test/fixtures/data.sql
+++ b/test/fixtures/data.sql
@@ -411,3 +411,6 @@ INSERT INTO zone VALUES (4, 'store 4', 3, 1);
 
 -- for foreign table projects_dump
 copy (select id, name, client_id from projects) to '/tmp/projects_dump.csv' with csv;
+
+TRUNCATE TABLE "UnitTest" CASCADE;
+INSERT INTO "UnitTest" VALUES (1, 'unit test 1');
diff --git a/test/fixtures/privileges.sql b/test/fixtures/privileges.sql
index b94dbb746..beced9875 100644
--- a/test/fixtures/privileges.sql
+++ b/test/fixtures/privileges.sql
@@ -79,6 +79,7 @@ GRANT ALL ON TABLE
     , space
     , zone
     , projects_dump
+    , "UnitTest"
 TO postgrest_test_anonymous;
 
 GRANT INSERT ON TABLE insertonly TO postgrest_test_anonymous;
diff --git a/test/fixtures/schema.sql b/test/fixtures/schema.sql
index 8ef333926..05df3f9d4 100755
--- a/test/fixtures/schema.sql
+++ b/test/fixtures/schema.sql
@@ -1451,3 +1451,8 @@ comment on foreign table projects_dump is
 $$A temporary projects dump
 
 Just a test for foreign tables$$;
+
+create table "UnitTest"(
+  "idUnitTest" integer primary key,
+  "nameUnitTest" text
+);