diff --git a/src/DfaFilter/SensitiveHelper.php b/src/DfaFilter/SensitiveHelper.php
index 36c69a7..357f187 100644
--- a/src/DfaFilter/SensitiveHelper.php
+++ b/src/DfaFilter/SensitiveHelper.php
@@ -95,7 +95,7 @@ public function setTree($sensitiveWords = null)
         $this->wordTree = new HashMap();
 
         foreach ($sensitiveWords as $word) {
-            $this->buildWordToTree($word);
+            $this->buildWordToTree(trim($word));
         }
         return $this;
     }