diff --git a/src/main/java/top/focess/qq/api/command/CommandSender.java b/src/main/java/top/focess/qq/api/command/CommandSender.java
index 2c04f5e..f77aea7 100755
--- a/src/main/java/top/focess/qq/api/command/CommandSender.java
+++ b/src/main/java/top/focess/qq/api/command/CommandSender.java
@@ -113,6 +113,7 @@ public Friend getFriend() {
      *
      * @return true if this CommandSender presents a Mirai Friend instance, false otherwise
      */
+    @EnsuresNonNullIf(expression = "getFriend()", result = true)
     public boolean isFriend() {
         return isFriend;
     }