diff --git a/modules/taxonomy/views_plugin_argument_default_taxonomy_tid.inc b/modules/taxonomy/views_plugin_argument_default_taxonomy_tid.inc
index f492a9a..5fd97d0 100644
--- a/modules/taxonomy/views_plugin_argument_default_taxonomy_tid.inc
+++ b/modules/taxonomy/views_plugin_argument_default_taxonomy_tid.inc
@@ -31,7 +31,7 @@ class views_plugin_argument_default_taxonomy_tid extends views_plugin_argument_d
     );
     $form[$this->option_name . '_node'] = array(
       '#type' => 'checkbox',
-      '#title' => t('Load default argument from node page, thats good for related taxonomy blocks'),
+      '#title' => t('Load default argument from node page (good for related taxonomy blocks)'),
       '#default_value' => $this->argument->options[$this->option_name . '_node'],
       '#process' => array('views_process_dependency'),
       '#dependency' => array(
@@ -41,6 +41,23 @@ class views_plugin_argument_default_taxonomy_tid extends views_plugin_argument_d
       '#dependency_count' => 2,
     );
 
+    $form[$this->option_name . '_operator'] = array(
+      '#type' => 'select',
+      '#title' => t('How to combine term IDs'),
+      '#description' => t("Whether to form multiple term IDs into the argument with '+' or ','."),
+      '#options' => array(
+        'and' => 'and',
+        'or'  => 'or',
+      ),
+      '#process' => array('views_process_dependency'),
+      '#dependency' => array(
+        'radio:options[default_action]' => array('default'),
+        'radio:options[default_argument_type]' => array($this->id),
+        'edit-options-default-taxonomy-tid-node' => array(1),
+      ),
+      '#dependency_count' => 3,
+    );
+
     $form[$this->option_name . '_limit'] = array(
       '#type' => 'checkbox',
       '#title' => t('Limit terms by vocabulary'),
@@ -104,12 +121,23 @@ class views_plugin_argument_default_taxonomy_tid extends views_plugin_argument_d
               $tids[] = $tid;
             }
           }
-          return implode(",", $tids);
         }
         // Return all tids.
         else {
-          return implode(",", array_keys($node->taxonomy));
+          $tids = array_keys($node->taxonomy);
+        }
+
+        // The argument is transformed to a string of tids, in the form
+        // of 1+2+3 (for OR) or 1,2,3 (for AND).
+        if ($this->argument->options[$this->option_name] == 'and') {
+          $glue = ',';
         }
+        else {
+          $glue = '+';
+        }
+
+        $argument_value = implode($glue, $tids);
+        return $argument_value;
       }
     }