diff --git a/src/mn-text-table.gob b/src/mn-text-table.gob
index b5f6cb5..6751d7e 100644
--- a/src/mn-text-table.gob
+++ b/src/mn-text-table.gob
@@ -90,14 +90,17 @@ class MN:Text:Table from Mn:Widget
     row_free (Row *row (check null))
   {
     mn_g_ptr_array_free_deep_custom(row->cells, (GFunc) self_cell_free, NULL);
+    row->cells = NULL;
     g_free(row);
   }
 
   private void
     cell_free (MNTextTableCell *cell (check null))
   {
-    if (cell->layout)
+    if (cell->layout) {
       g_object_unref(cell->layout);
+      cell->layout = NULL;
+    }
     g_free(cell);
   }
 
diff --git a/src/mn-tooltips.gob b/src/mn-tooltips.gob
index 2f9da32..b01c4d7 100644
--- a/src/mn-tooltips.gob
+++ b/src/mn-tooltips.gob
@@ -88,17 +88,18 @@ class MN:Tooltips from G:Object
     GSList *data_list_copy;
     GSList *l;
 
-    if (selfp->timeout_id)
+    if (selfp->timeout_id) {
       g_source_remove(selfp->timeout_id);
+      selfp->timeout_id = 0;
+    }
 
-      /* Create a copy of the list to avoid memory corruption as the
-       * self_widget_remove call removes the item from selfp->data_list */
-      data_list_copy = g_slist_copy(selfp->data_list);
-      MN_LIST_FOREACH(l, data_list_copy)
-      {
-	TooltipsData *data = l->data;
-	self_widget_remove(data->widget, data);
-      }
+    /* Create a copy of the list to avoid memory corruption as the
+     * self_widget_remove call removes the item from selfp->data_list */
+    data_list_copy = g_slist_copy(selfp->data_list);
+    MN_LIST_FOREACH(l, data_list_copy) {
+      TooltipsData *data = l->data;
+      self_widget_remove(data->widget, data);
+    }
 
     g_slist_free(data_list_copy);
     self_unset_window(self);
@@ -115,7 +116,9 @@ class MN:Tooltips from G:Object
 
     g_object_set_data(G_OBJECT(data->widget), TOOLTIPS_DATA, NULL);
     g_object_unref(data->widget);
+    data->widget = NULL;
     g_object_unref(data->tip_widget);
+    data->tip_widget = NULL;
     g_free(data);
   }
 
@@ -139,11 +142,11 @@ class MN:Tooltips from G:Object
   private void
     unset_window (self)
   {
-    if (selfp->window)
-      {
-	self_disconnect_display_closed(self);
-	gtk_widget_destroy(selfp->window);
-      }
+    if (selfp->window) {
+      self_disconnect_display_closed(self);
+      gtk_widget_destroy(selfp->window);
+      selfp->window = NULL;
+    }
   }
 
   private void