diff --git a/runners/core-java/src/main/java/org/apache/beam/runners/core/metrics/BoundedTrieCell.java b/runners/core-java/src/main/java/org/apache/beam/runners/core/metrics/BoundedTrieCell.java
index e749fed73c2c..34beaa6b63ed 100644
--- a/runners/core-java/src/main/java/org/apache/beam/runners/core/metrics/BoundedTrieCell.java
+++ b/runners/core-java/src/main/java/org/apache/beam/runners/core/metrics/BoundedTrieCell.java
@@ -17,6 +17,7 @@
  */
 package org.apache.beam.runners.core.metrics;
 
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import java.util.Arrays;
 import java.util.Objects;
 import org.apache.beam.sdk.metrics.BoundedTrie;
@@ -31,6 +32,9 @@
  * In that case retrieving the underlying cell and reporting directly to it avoids a step of
  * indirection.
  */
+@SuppressFBWarnings(
+    value = "IS2_INCONSISTENT_SYNC",
+    justification = "Some access on purpose are left unsynchronized")
 public class BoundedTrieCell implements BoundedTrie, MetricCell<BoundedTrieData> {
 
   private final DirtyState dirty = new DirtyState();
diff --git a/runners/core-java/src/main/java/org/apache/beam/runners/core/metrics/BoundedTrieData.java b/runners/core-java/src/main/java/org/apache/beam/runners/core/metrics/BoundedTrieData.java
index 049ba5c93967..b1efa59fba33 100644
--- a/runners/core-java/src/main/java/org/apache/beam/runners/core/metrics/BoundedTrieData.java
+++ b/runners/core-java/src/main/java/org/apache/beam/runners/core/metrics/BoundedTrieData.java
@@ -17,6 +17,7 @@
  */
 package org.apache.beam.runners.core.metrics;
 
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -55,6 +56,9 @@
 @SuppressWarnings({
   "nullness" // TODO(https://github.com/apache/beam/issues/20497)
 })
+@SuppressFBWarnings(
+    value = "IS2_INCONSISTENT_SYNC",
+    justification = "Some access on purpose are left unsynchronized")
 public class BoundedTrieData implements Serializable {
 
   private static final int DEFAULT_BOUND = 100; // Default maximum size of the trie