diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9494208..0ce3323 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,9 @@ All notable changes to this project will be documented in this file.
   There are actually only two generic types in GraphQL: Scalars and objects.
   Enum is a scalar value.
 
+### Fixed
+- Parsing block string values.
+
 ## [0.5.0.0] - 2019-08-14
 ### Added
 - `executeWithName` executes an operation with the given name.
diff --git a/src/Language/GraphQL/Parser.hs b/src/Language/GraphQL/Parser.hs
index 17482d7..5ae71b2 100644
--- a/src/Language/GraphQL/Parser.hs
+++ b/src/Language/GraphQL/Parser.hs
@@ -108,8 +108,8 @@ value = ValueVariable <$> variable
     <|> ValueInt      <$> integer
     <|> ValueBoolean  <$> booleanValue
     <|> ValueNull     <$  symbol "null"
-    <|> ValueString   <$> string
     <|> ValueString   <$> blockString
+    <|> ValueString   <$> string
     <|> ValueEnum     <$> try enumValue
     <|> ValueList     <$> listValue
     <|> ValueObject   <$> objectValue
diff --git a/tests/Language/GraphQL/ParserSpec.hs b/tests/Language/GraphQL/ParserSpec.hs
index c412c85..6425ea5 100644
--- a/tests/Language/GraphQL/ParserSpec.hs
+++ b/tests/Language/GraphQL/ParserSpec.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE QuasiQuotes #-}
 module Language.GraphQL.ParserSpec
     ( spec
     ) where
@@ -11,8 +12,19 @@ import Test.Hspec ( Spec
                   , shouldSatisfy
                   )
 import Text.Megaparsec (parse)
+import Text.RawString.QQ (r)
 
 spec :: Spec
-spec = describe "Parser" $
+spec = describe "Parser" $ do
     it "accepts BOM header" $
         parse document "" "\xfeff{foo}" `shouldSatisfy` isRight
+
+    it "accepts block strings as argument" $
+        parse document "" [r|{
+              hello(text: """Argument""")
+            }|] `shouldSatisfy` isRight
+
+    it "accepts strings as argument" $
+        parse document "" [r|{
+              hello(text: "Argument")
+            }|] `shouldSatisfy` isRight