diff --git a/lib/grant-types/abstract-grant-type.js b/lib/grant-types/abstract-grant-type.js
index 4fd02437..11d086e7 100644
--- a/lib/grant-types/abstract-grant-type.js
+++ b/lib/grant-types/abstract-grant-type.js
@@ -97,7 +97,7 @@ AbstractGrantType.prototype.validateScope = async function(user, client, scope)
 
     return validatedScope;
   } else {
-    return scope;
+    return Promise.resolve(scope);
   }
 };
 
diff --git a/lib/grant-types/authorization-code-grant-type.js b/lib/grant-types/authorization-code-grant-type.js
index 2101462b..22e1823c 100644
--- a/lib/grant-types/authorization-code-grant-type.js
+++ b/lib/grant-types/authorization-code-grant-type.js
@@ -207,6 +207,7 @@ class AuthorizationCodeGrantType extends AbstractGrantType {
   }
 }
 
+
 /**
  * Export constructor.
  */
diff --git a/test/integration/grant-types/authorization-code-grant-type_test.js b/test/integration/grant-types/authorization-code-grant-type_test.js
index a4d69c40..3e0da229 100644
--- a/test/integration/grant-types/authorization-code-grant-type_test.js
+++ b/test/integration/grant-types/authorization-code-grant-type_test.js
@@ -88,7 +88,7 @@ describe('AuthorizationCodeGrantType integration', function() {
         e.message.should.equal('Missing parameter: `request`');
       }
     });
-    
+
     it('should throw an error if `client` is invalid', function() {
       const client = {};
       const model = {
@@ -108,7 +108,7 @@ describe('AuthorizationCodeGrantType integration', function() {
     });
 
     it('should throw an error if `client` is missing', function() {
-      
+
       const model = {
         getAuthorizationCode: function() { return { authorizationCode: 12345, expiresAt: new Date(new Date() * 2), user: {} }; },
         revokeAuthorizationCode: function() {},
diff --git a/test/unit/grant-types/authorization-code-grant-type_test.js b/test/unit/grant-types/authorization-code-grant-type_test.js
index c3502bee..c98aa156 100644
--- a/test/unit/grant-types/authorization-code-grant-type_test.js
+++ b/test/unit/grant-types/authorization-code-grant-type_test.js
@@ -72,7 +72,7 @@ describe('AuthorizationCodeGrantType', function() {
       };
       const handler = new AuthorizationCodeGrantType({ accessTokenLifetime: 120, model: model });
 
-      sinon.stub(handler, 'validateScope').returns('foobiz');
+      sinon.stub(handler, 'validateScope').returns(Promise.resolve('foobiz'));
       sinon.stub(handler, 'generateAccessToken').returns(Promise.resolve('foo'));
       sinon.stub(handler, 'generateRefreshToken').returns(Promise.resolve('bar'));
       sinon.stub(handler, 'getAccessTokenExpiresAt').returns(Promise.resolve('biz'));
@@ -86,6 +86,37 @@ describe('AuthorizationCodeGrantType', function() {
           model.saveToken.firstCall.args[1].should.equal(client);
           model.saveToken.firstCall.args[2].should.equal(user);
           model.saveToken.firstCall.thisValue.should.equal(model);
+          handler.validateScope.callCount.should.equal(1);
+        })
+        .catch(should.fail);
+    });
+  });
+
+  describe('saveToken() - no scope', function() {
+    it('should call `model.saveToken()`', function() {
+      const client = {};
+      const user = {};
+      const model = {
+        getAuthorizationCode: function() {},
+        revokeAuthorizationCode: function() {},
+        saveToken: sinon.stub().returns(true),
+        validateScope: function(u, c, s){ return null; }
+      };
+      const handler = new AuthorizationCodeGrantType({ accessTokenLifetime: 120, model: model });
+
+      sinon.stub(handler, 'generateAccessToken').returns(Promise.resolve('foo'));
+      sinon.stub(handler, 'generateRefreshToken').returns(Promise.resolve('bar'));
+      sinon.stub(handler, 'getAccessTokenExpiresAt').returns(Promise.resolve('biz'));
+      sinon.stub(handler, 'getRefreshTokenExpiresAt').returns(Promise.resolve('baz'));
+
+      return handler.saveToken(user, client, 'foobar', null)
+        .then(function() {
+          model.saveToken.callCount.should.equal(1);
+          model.saveToken.firstCall.args.should.have.length(3);
+          model.saveToken.firstCall.args[0].should.eql({ accessToken: 'foo', authorizationCode: 'foobar', accessTokenExpiresAt: 'biz', refreshToken: 'bar', refreshTokenExpiresAt: 'baz', scope: null });
+          model.saveToken.firstCall.args[1].should.equal(client);
+          model.saveToken.firstCall.args[2].should.equal(user);
+          model.saveToken.firstCall.thisValue.should.equal(model);
         })
         .catch(should.fail);
     });