diff --git a/src/main/java/com/cnblogs/hoojo/sensitivewords/filter/dfa/executor/DfaFilterExecutor.java b/src/main/java/com/cnblogs/hoojo/sensitivewords/filter/dfa/executor/DfaFilterExecutor.java
index fb87ba5..fcb6207 100644
--- a/src/main/java/com/cnblogs/hoojo/sensitivewords/filter/dfa/executor/DfaFilterExecutor.java
+++ b/src/main/java/com/cnblogs/hoojo/sensitivewords/filter/dfa/executor/DfaFilterExecutor.java
@@ -60,9 +60,9 @@ protected boolean put(String word) throws RuntimeException {
 			} 
 			if (nextNode == null) {
 				nextNode = new DfaNode(nextChar);
+				node.addChild(nextNode);
 			}
-			
-			node.addChild(nextNode);
+
 			node = nextNode;
 			
 			if (i == word.length() - 1) {
diff --git a/src/main/java/com/cnblogs/hoojo/sensitivewords/filter/tire/executor/TireTreeFilterExecutor.java b/src/main/java/com/cnblogs/hoojo/sensitivewords/filter/tire/executor/TireTreeFilterExecutor.java
index e3db034..dead2b9 100644
--- a/src/main/java/com/cnblogs/hoojo/sensitivewords/filter/tire/executor/TireTreeFilterExecutor.java
+++ b/src/main/java/com/cnblogs/hoojo/sensitivewords/filter/tire/executor/TireTreeFilterExecutor.java
@@ -124,9 +124,9 @@ protected boolean put(String word) throws RuntimeException {
 			} 
 			if (nextNode == null) {
 				nextNode = new TireTreeNode(nextChar);
+				node.addChild(nextNode);
 			}
-			
-			node.addChild(nextNode);
+
 			node = nextNode;
 			
 			if (i == word.length() - 1) {