diff --git a/unittest-core.py b/unittest-core.py
index bad2dcf90..c10ee9613 100755
--- a/unittest-core.py
+++ b/unittest-core.py
@@ -88,7 +88,7 @@ def _common_plugin_tests(self, plugin):
 
         # Check stats
         self.assertIsInstance(plugin_instance.get_raw(), (dict, list))
-        if isinstance(plugin_instance.get_raw(), dict):
+        if isinstance(plugin_instance.get_raw(), dict) and plugin_instance.get_raw() != {}:
             res = False
             for f in plugin_instance.fields_description:
                 if f not in plugin_instance.get_raw():
@@ -96,7 +96,7 @@ def _common_plugin_tests(self, plugin):
                 else:
                     res = True
             self.assertTrue(res)
-        elif isinstance(plugin_instance.get_raw(), list):
+        elif isinstance(plugin_instance.get_raw(), list) and len(plugin_instance.get_raw()) > 0:
             res = False
             for i in plugin_instance.get_raw():
                 for f in i:
@@ -592,10 +592,10 @@ def test_099_output_bars(self):
         bar.percent = 110
         self.assertEqual(bar.get(), '|||||||||||||||||||||||||||||||||||||||||||| >100%')
 
-    # def test_100_system_plugin_method(self):
-    #     """Test system plugin methods"""
-    #     print('INFO: [TEST_100] Test system plugin methods')
-    #     self._common_plugin_tests('system')
+    def test_100_system_plugin_method(self):
+        """Test system plugin methods"""
+        print('INFO: [TEST_100] Test system plugin methods')
+        self._common_plugin_tests('system')
 
     def test_101_cpu_plugin_method(self):
         """Test cpu plugin methods"""
@@ -623,10 +623,10 @@ def test_105_network_plugin_method(self):
         print('INFO: [TEST_105] Test network plugin methods')
         self._common_plugin_tests('network')
 
-    # def test_106_diskio_plugin_method(self):
-    #     """Test diskio plugin methods"""
-    #     print('INFO: [TEST_106] Test diskio plugin methods')
-    #     self._common_plugin_tests('diskio')
+    def test_106_diskio_plugin_method(self):
+        """Test diskio plugin methods"""
+        print('INFO: [TEST_106] Test diskio plugin methods')
+        self._common_plugin_tests('diskio')
 
     def test_107_fs_plugin_method(self):
         """Test fs plugin methods"""