diff --git a/src/java.base/share/classes/java/io/PipedOutputStream.java b/src/java.base/share/classes/java/io/PipedOutputStream.java
index 525a4c73996..8e7bf124272 100644
--- a/src/java.base/share/classes/java/io/PipedOutputStream.java
+++ b/src/java.base/share/classes/java/io/PipedOutputStream.java
@@ -163,6 +163,7 @@ public class PipedOutputStream extends OutputStream {
      */
     @Override
     public synchronized void flush() throws IOException {
+        var sink = this.sink;
         if (sink != null) {
             synchronized (sink) {
                 sink.notifyAll();