diff --git a/atom/browser/api/atom_api_system_preferences_mac.mm b/atom/browser/api/atom_api_system_preferences_mac.mm
index aee0b4631613..edb875c0b243 100644
--- a/atom/browser/api/atom_api_system_preferences_mac.mm
+++ b/atom/browser/api/atom_api_system_preferences_mac.mm
@@ -28,17 +28,17 @@ std::map<int, id> g_id_map;
 
 }  // namespace
 
-void SystemPreferences::PostNotification(const std::string& name, 
+void SystemPreferences::PostNotification(const std::string& name,
     const base::DictionaryValue& user_info) {
   DoPostNotification(name, user_info, false);
 }
 
-void SystemPreferences::PostLocalNotification(const std::string& name, 
+void SystemPreferences::PostLocalNotification(const std::string& name,
     const base::DictionaryValue& user_info) {
   DoPostNotification(name, user_info, true);
 }
 
-void SystemPreferences::DoPostNotification(const std::string& name, 
+void SystemPreferences::DoPostNotification(const std::string& name,
     const base::DictionaryValue& user_info, bool is_local) {
   NSNotificationCenter* center = is_local ?
     [NSNotificationCenter defaultCenter] :
@@ -128,11 +128,17 @@ v8::Local<v8::Value> SystemPreferences::GetUserDefault(
     return mate::ConvertToV8(isolate(),
       net::GURLWithNSURL([defaults URLForKey:key]));
   } else if (type == "array") {
-    return mate::ConvertToV8(isolate(),
-      *NSArrayToListValue([defaults arrayForKey:key]));
+    std::unique_ptr<base::ListValue> list =
+        NSArrayToListValue([defaults arrayForKey:key]);
+    if (list == nullptr)
+      list.reset(new base::ListValue());
+    return mate::ConvertToV8(isolate(), *list);
   } else if (type == "dictionary") {
-    return mate::ConvertToV8(isolate(),
-      *NSDictionaryToDictionaryValue([defaults dictionaryForKey:key]));
+    std::unique_ptr<base::DictionaryValue> dictionary =
+        NSDictionaryToDictionaryValue([defaults dictionaryForKey:key]);
+    if (dictionary == nullptr)
+      dictionary.reset(new base::DictionaryValue());
+    return mate::ConvertToV8(isolate(), *dictionary);
   } else {
     return v8::Undefined(isolate());
   }
diff --git a/spec/api-system-preferences-spec.js b/spec/api-system-preferences-spec.js
index e61ae726dfcc..e893a7c55e24 100644
--- a/spec/api-system-preferences-spec.js
+++ b/spec/api-system-preferences-spec.js
@@ -37,14 +37,26 @@ describe('systemPreferences module', function () {
     }
 
     it('returns values for known user defaults', function () {
-      let locale = systemPreferences.getUserDefault('AppleLocale', 'string')
-      assert.notEqual(locale, null)
+      const locale = systemPreferences.getUserDefault('AppleLocale', 'string')
+      assert.equal(typeof locale, 'string')
       assert(locale.length > 0)
 
-      let languages = systemPreferences.getUserDefault('AppleLanguages', 'array')
-      assert.notEqual(languages, null)
+      const languages = systemPreferences.getUserDefault('AppleLanguages', 'array')
+      assert(Array.isArray(languages))
       assert(languages.length > 0)
     })
+
+    it('returns values for unknown user defaults', function () {
+      assert.equal(systemPreferences.getUserDefault('UserDefaultDoesNotExist', 'boolean'), false)
+      assert.equal(systemPreferences.getUserDefault('UserDefaultDoesNotExist', 'integer'), 0)
+      assert.equal(systemPreferences.getUserDefault('UserDefaultDoesNotExist', 'float'), 0)
+      assert.equal(systemPreferences.getUserDefault('UserDefaultDoesNotExist', 'double'), 0)
+      assert.equal(systemPreferences.getUserDefault('UserDefaultDoesNotExist', 'string'), '')
+      assert.equal(systemPreferences.getUserDefault('UserDefaultDoesNotExist', 'url'), '')
+      assert.equal(systemPreferences.getUserDefault('UserDefaultDoesNotExist', 'badtype'), undefined)
+      assert.deepEqual(systemPreferences.getUserDefault('UserDefaultDoesNotExist', 'array'), [])
+      assert.deepEqual(systemPreferences.getUserDefault('UserDefaultDoesNotExist', 'dictionary'), {})
+    })
   })
 
   describe('systemPreferences.isInvertedColorScheme()', function () {