diff --git a/src/Effect/Aff.js b/src/Effect/Aff.js
index 3edf456..4cbe0ae 100644
--- a/src/Effect/Aff.js
+++ b/src/Effect/Aff.js
@@ -498,7 +498,11 @@ var Aff = function () {
               // bracket count is non-zero then we are in a masked state so it's
               // impossible to be killed.
               if (interrupt && interrupt !== tmp && bracketCount === 0) {
-                step = attempt._1.killed(util.fromLeft(interrupt))(attempt._2);
+                if (util.isLeft(step)) {
+                  step = attempt._1.killed(util.fromLeft(interrupt))(attempt._2);
+                } else {
+                  step = attempt._1.completed(util.fromRight(step))(attempt._2);
+                }
               } else if (fail) {
                 step = attempt._1.failed(util.fromLeft(fail))(attempt._2);
               } else {