diff --git a/api/v1/entries/productissues.php b/api/v1/entries/productissues.php
index 2769896bd3..294cbe18ee 100644
--- a/api/v1/entries/productissues.php
+++ b/api/v1/entries/productissues.php
@@ -92,8 +92,13 @@ class productIssuesEntry extends entry
             $taskTypeMap  = array_flip($this->app->lang->task->typeList);
             $bugTypeMap   = array_flip($this->app->lang->bug->typeList);
 
+            $labelExistStatus = array(); /* Set this value to judge if label is not exist. Exist => true, not Exist => false. */
+            $objectTypeMap = array_merge(array_keys(array_merge($storyTypeMap, $taskTypeMap, $bugTypeMap)), array($this->app->lang->story->common, $this->app->lang->task->common, $this->app->lang->bug->common));
             foreach($labels as $label)
             {
+                /* Set label exist status. */
+                $labelExistStatus[$label] = in_array($label, $objectTypeMap) ? true : false;
+
                 if($label == $this->app->lang->story->common) $storyFilter[] = 'all';
                 if(isset($storyTypeMap[$label])) $storyFilter[] = $storyTypeMap[$label];
 
@@ -103,6 +108,9 @@ class productIssuesEntry extends entry
                 if($label == $this->app->lang->bug->common) $bugFilter[] = 'all';
                 if(isset($bugTypeMap[$label])) $bugFilter[] = $bugTypeMap[$label];
             }
+
+            /* Return empty result if one label is not exists. We assume user usually input one label to search by labels. */
+            if(in_array(false, $labelExistStatus) and empty($storyFilter) and empty($taskFilter) and empty($bugFilter)) $this->send(200, array('page' => $page, 'total' => 0, 'limit' => $limit, 'issues' => array()));
         }
 
         if(!empty($storyFilter)) $labelTypes[] = 'story';