diff --git a/clients/src/main/java/org/apache/kafka/clients/consumer/internals/AbstractCoordinator.java b/clients/src/main/java/org/apache/kafka/clients/consumer/internals/AbstractCoordinator.java
index 9860d2f5890..b530ca562b9 100644
--- a/clients/src/main/java/org/apache/kafka/clients/consumer/internals/AbstractCoordinator.java
+++ b/clients/src/main/java/org/apache/kafka/clients/consumer/internals/AbstractCoordinator.java
@@ -1577,7 +1577,9 @@ public abstract class AbstractCoordinator implements Closeable {
                     this.failed.set(new RuntimeException(e));
             } finally {
                 log.debug("Heartbeat thread has closed");
-                this.closed = true;
+                synchronized (AbstractCoordinator.this) {
+                    this.closed = true;
+                }
             }
         }