diff --git a/jraft-core/src/main/java/com/alipay/sofa/jraft/core/Replicator.java b/jraft-core/src/main/java/com/alipay/sofa/jraft/core/Replicator.java
index 9a1ceba35..da66b75ad 100644
--- a/jraft-core/src/main/java/com/alipay/sofa/jraft/core/Replicator.java
+++ b/jraft-core/src/main/java/com/alipay/sofa/jraft/core/Replicator.java
@@ -445,9 +445,9 @@ void installSnapshot() {
             id.unlock();
             return;
         }
-        Requires.requireTrue(this.reader == null);
         boolean doUnlock = true;
         try {
+            Requires.requireTrue(this.reader == null);
             reader = options.getSnapshotStorage().open();
             if (reader == null) {
                 final NodeImpl node = options.getNode();