diff --git a/graphene/core/types/custom_scalars.py b/graphene/core/types/custom_scalars.py
index bd33df76..c1346c0a 100644
--- a/graphene/core/types/custom_scalars.py
+++ b/graphene/core/types/custom_scalars.py
@@ -16,11 +16,11 @@ class JSONString(Scalar):
     @staticmethod
     def parse_literal(node):
         if isinstance(node, ast.StringValue):
-            return json.dumps(node.value)
+            return json.loads(node.value)
 
     @staticmethod
     def parse_value(value):
-        return json.dumps(value)
+        return json.loads(value)
 
 
 class DateTime(Scalar):