diff --git a/src/main/java/cn/nukkit/Server.java b/src/main/java/cn/nukkit/Server.java
index a2399dee025..178aabdcf55 100644
--- a/src/main/java/cn/nukkit/Server.java
+++ b/src/main/java/cn/nukkit/Server.java
@@ -2201,7 +2201,7 @@ public boolean isWhitelisted(String name) {
     }
 
     public boolean isOp(String name) {
-        return this.operators.exists(name, true);
+        return name != null && this.operators.exists(name, true);
     }
 
     public Config getWhitelist() {