diff --git a/src/main/java/com/googlesource/gerrit/plugins/multisite/validation/dfsrefdb/SharedRefDatabase.java b/src/main/java/com/googlesource/gerrit/plugins/multisite/validation/dfsrefdb/SharedRefDatabase.java
index b475a72..87ebc96 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/multisite/validation/dfsrefdb/SharedRefDatabase.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/multisite/validation/dfsrefdb/SharedRefDatabase.java
@@ -120,11 +120,10 @@
   /**
    * Some references should not be stored in the SharedRefDatabase.
    *
-   * @param ref
+   * @param refName
    * @return true if it's to be ignore; false otherwise
    */
-  default boolean ignoreRefInSharedDb(Ref ref) {
-    String refName = ref.getName();
+  default boolean ignoreRefInSharedDb(String refName) {
     return refName == null
         || refName.startsWith("refs/draft-comments")
         || (refName.startsWith("refs/changes") && !refName.endsWith("/meta"));
diff --git a/src/main/java/com/googlesource/gerrit/plugins/multisite/validation/dfsrefdb/zookeeper/ZkSharedRefDatabase.java b/src/main/java/com/googlesource/gerrit/plugins/multisite/validation/dfsrefdb/zookeeper/ZkSharedRefDatabase.java
index 97f6be5..503d93f 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/multisite/validation/dfsrefdb/zookeeper/ZkSharedRefDatabase.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/multisite/validation/dfsrefdb/zookeeper/ZkSharedRefDatabase.java
@@ -43,12 +43,12 @@
 
   @Override
   public boolean compareAndRemove(String project, Ref oldRef) throws IOException {
-    return ignoreRefInSharedDb(oldRef) || compareAndPut(project, oldRef, NULL_REF);
+    return compareAndPut(project, oldRef, NULL_REF);
   }
 
   @Override
   public boolean compareAndPut(String projectName, Ref oldRef, Ref newRef) throws IOException {
-    if (newRef != NULL_REF && ignoreRefInSharedDb(newRef)) {
+    if (ignoreRefInSharedDb(MoreObjects.firstNonNull(oldRef.getName(), newRef.getName()))) {
       return true;
     }
 
diff --git a/src/test/java/com/googlesource/gerrit/plugins/multisite/validation/dfsrefdb/zookeeper/ZkSharedRefDatabaseTest.java b/src/test/java/com/googlesource/gerrit/plugins/multisite/validation/dfsrefdb/zookeeper/ZkSharedRefDatabaseTest.java
index bcdf475..c3f3ace 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/multisite/validation/dfsrefdb/zookeeper/ZkSharedRefDatabaseTest.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/multisite/validation/dfsrefdb/zookeeper/ZkSharedRefDatabaseTest.java
@@ -161,32 +161,51 @@
   @Test
   public void anImmutableChangeShouldBeIgnored() {
     Ref immutableChangeRef = zkSharedRefDatabase.newRef(A_REF_NAME_OF_A_PATCHSET, AN_OBJECT_ID_1);
-    assertThat(zkSharedRefDatabase.ignoreRefInSharedDb(immutableChangeRef)).isTrue();
+    assertThat(zkSharedRefDatabase.ignoreRefInSharedDb(immutableChangeRef.getName())).isTrue();
   }
 
   @Test
   public void aChangeMetaShouldNotBeIgnored() {
     Ref immutableChangeRef = zkSharedRefDatabase.newRef("refs/changes/01/1/meta", AN_OBJECT_ID_1);
-    assertThat(zkSharedRefDatabase.ignoreRefInSharedDb(immutableChangeRef)).isFalse();
+    assertThat(zkSharedRefDatabase.ignoreRefInSharedDb(immutableChangeRef.getName())).isFalse();
   }
 
   @Test
   public void aDraftCommentsShouldBeIgnored() {
     Ref immutableChangeRef =
         zkSharedRefDatabase.newRef("refs/draft-comments/01/1/1000000", AN_OBJECT_ID_1);
-    assertThat(zkSharedRefDatabase.ignoreRefInSharedDb(immutableChangeRef)).isTrue();
+    assertThat(zkSharedRefDatabase.ignoreRefInSharedDb(immutableChangeRef.getName())).isTrue();
   }
 
   @Test
   public void regularRefHeadsMasterShouldNotBeIgnored() {
     Ref immutableChangeRef = zkSharedRefDatabase.newRef("refs/heads/master", AN_OBJECT_ID_1);
-    assertThat(zkSharedRefDatabase.ignoreRefInSharedDb(immutableChangeRef)).isFalse();
+    assertThat(zkSharedRefDatabase.ignoreRefInSharedDb(immutableChangeRef.getName())).isFalse();
   }
 
   @Test
   public void regularCommitShouldNotBeIgnored() {
     Ref immutableChangeRef = zkSharedRefDatabase.newRef("refs/heads/stable-2.16", AN_OBJECT_ID_1);
-    assertThat(zkSharedRefDatabase.ignoreRefInSharedDb(immutableChangeRef)).isFalse();
+    assertThat(zkSharedRefDatabase.ignoreRefInSharedDb(immutableChangeRef.getName())).isFalse();
+  }
+
+  @Test
+  public void compareAndPutShouldAlwaysIngoreAlwaysDraftCommentsEvenOutOfOrder() throws Exception {
+    // Test to reproduce a production bug where ignored refs were persisted in ZK because
+    // newRef == NULL
+    Ref existingRef =
+        zkSharedRefDatabase.newRef("refs/draft-comments/56/450756/1013728", AN_OBJECT_ID_1);
+    Ref oldRefToIgnore =
+        zkSharedRefDatabase.newRef("refs/draft-comments/56/450756/1013728", AN_OBJECT_ID_2);
+    Ref nullRef = SharedRefDatabase.NULL_REF;
+    String projectName = A_TEST_PROJECT_NAME;
+
+    // This ref should be ignored even if newRef is null
+    assertThat(zkSharedRefDatabase.compareAndPut(A_TEST_PROJECT_NAME, existingRef, nullRef))
+        .isTrue();
+
+    // This ignored ref should also be ignored
+    assertThat(zkSharedRefDatabase.compareAndPut(projectName, oldRefToIgnore, nullRef)).isTrue();
   }
 
   @Override