diff --git a/src/threads.js b/src/threads.js
index f1ff6ade..1025e3a9 100644
--- a/src/threads.js
+++ b/src/threads.js
@@ -2278,6 +2278,7 @@ Process.prototype.reportKeep = function (predicate, list) {
                 this.context.accumulator.source.cdr();
         }
         if (this.context.accumulator.remaining === 0) {
+            this.context.accumulator.end.rest = new List();
             this.returnValueToParentContext(
                 this.context.accumulator.target.cdr()
             );