diff --git a/lib/internal/abort_controller.js b/lib/internal/abort_controller.js
index a24b5b556e1a5e..09b160e9fe5aa8 100644
--- a/lib/internal/abort_controller.js
+++ b/lib/internal/abort_controller.js
@@ -522,6 +522,13 @@ function abortSignal(signal, reason) {
   for (let i = 0; i < dependentSignalsToAbort.length; i++) {
     const dependentSignal = dependentSignalsToAbort[i];
     runAbort(dependentSignal);
+    // A transitively-aborted dependent signal can never abort again, so there
+    // is no longer any reason to keep it alive. Dropping it from
+    // gcPersistentSignals lets it be collected, which in turn prunes its
+    // WeakRef from its sources' kDependantSignals sets. Otherwise, an observed
+    // composite that follows a long-lived source stays retained forever and
+    // its entry accumulates in that source's kDependantSignals.
+    gcPersistentSignals.delete(dependentSignal);
   }
 
   // Clean up the signal from gcPersistentSignals
diff --git a/test/parallel/test-abortsignal-drop-settled-signals.mjs b/test/parallel/test-abortsignal-drop-settled-signals.mjs
index c481db069d6f13..224d65abc70f5f 100644
--- a/test/parallel/test-abortsignal-drop-settled-signals.mjs
+++ b/test/parallel/test-abortsignal-drop-settled-signals.mjs
@@ -142,6 +142,37 @@ describe('when there is a long-lived signal', () => {
 
     run(1);
   });
+
+  it('drops observed dependent signals once they are transitively aborted', async () => {
+    const longLived = new AbortController();
+    const handler = () => {};
+    const size = () => {
+      const sym = Object.getOwnPropertySymbols(longLived.signal).find(
+        (s) => s.toString() === 'Symbol(kDependantSignals)'
+      );
+      return sym ? longLived.signal[sym].size : 0;
+    };
+
+    // Each composite observes the long-lived source and a per-request source,
+    // then is aborted through the per-request source without ever removing its
+    // listener. The aborted composites can never fire again, so the long-lived
+    // source's dependant set must not accumulate them. Using a helper keeps the
+    // last iteration's signals from lingering on the stack for the assertion.
+    const createObservedAbortedComposite = () => {
+      const perReq = new AbortController();
+      const composite = AbortSignal.any([perReq.signal, longLived.signal]);
+      composite.addEventListener('abort', handler);
+      perReq.abort();
+    };
+    for (let i = 0; i < limit; i++) {
+      createObservedAbortedComposite();
+    }
+
+    await gcUntil(
+      'observed dependents are dropped after transitive abort',
+      () => size() === 0,
+    );
+  });
 });
 
 it('does not prevent source signal from being GCed if it is short-lived', (t, done) => {