diff --git a/broker/src/main/java/io/moquette/persistence/MemoryMessagesStore.java b/broker/src/main/java/io/moquette/persistence/MemoryMessagesStore.java
index 87b5c878..1168ed84 100755
--- a/broker/src/main/java/io/moquette/persistence/MemoryMessagesStore.java
+++ b/broker/src/main/java/io/moquette/persistence/MemoryMessagesStore.java
@@ -2229,7 +2229,7 @@ public class MemoryMessagesStore implements IMessagesStore {
     public boolean addSensitiveWords(List<String> words) {
         for (String word :
             words) {
-            databaseStore.persistSensitiveWord(word);
+            databaseStore.persistSensitiveWord(word.toLowerCase());
         }
         lastUpdateSensitiveTime = 0;
         return true;
diff --git a/broker/src/main/java/win/liyufan/im/SensitiveFilter.java b/broker/src/main/java/win/liyufan/im/SensitiveFilter.java
index e08de840..693d1070 100644
--- a/broker/src/main/java/win/liyufan/im/SensitiveFilter.java
+++ b/broker/src/main/java/win/liyufan/im/SensitiveFilter.java
@@ -58,6 +58,7 @@ public class SensitiveFilter {
             return sensitiveWords;
         }
 
+        text = text.toLowerCase();
         for(int i=0;i<text.length();i++){
             int sensitiveWordLength = getSensitiveWordLength(text, i, matchType);
             if(sensitiveWordLength>0){