diff --git a/basis/core-foundation/run-loop/run-loop.factor b/basis/core-foundation/run-loop/run-loop.factor
index b0c4d640c1..f632a6c462 100644
--- a/basis/core-foundation/run-loop/run-loop.factor
+++ b/basis/core-foundation/run-loop/run-loop.factor
@@ -126,6 +126,7 @@ PRIVATE>
     60 timer-callback <CFTimer> add-timer-to-run-loop ;
 
 : run-one-iteration ( nanos -- handled? )
+    reset-run-loop
     CFRunLoopDefaultMode
     swap [ nanoseconds ] [ 5 minutes ] if* >CFTimeInterval
     t CFRunLoopRunInMode kCFRunLoopRunHandledSource = ;