diff --git a/src/engine/runtime.js b/src/engine/runtime.js
index 122750fb..a14f1546 100644
--- a/src/engine/runtime.js
+++ b/src/engine/runtime.js
@@ -662,6 +662,7 @@ class Runtime extends EventEmitter {
                 continue;
             }
             if (this.threads[i].target === target) {
+                this.threads[i].isKilled = true;
                 this._removeThread(this.threads[i]);
             }
         }
diff --git a/src/engine/sequencer.js b/src/engine/sequencer.js
index c8051c87..d5c79eae 100644
--- a/src/engine/sequencer.js
+++ b/src/engine/sequencer.js
@@ -69,6 +69,9 @@ class Sequencer {
                     // Normal-mode thread: step.
                     this.stepThread(activeThread);
                     activeThread.warpTimer = null;
+                    if (activeThread.isKilled) {
+                        i--;    // if the thread is removed from the list (killed), do not increase index
+                    }
                 }
                 if (activeThread.status === Thread.STATUS_RUNNING) {
                     numActiveThreads++;
diff --git a/src/engine/thread.js b/src/engine/thread.js
index 208ff1e9..3b8ce32b 100644
--- a/src/engine/thread.js
+++ b/src/engine/thread.js
@@ -30,6 +30,12 @@ class Thread {
          */
         this.status = 0; /* Thread.STATUS_RUNNING */
 
+        /**
+         * Whether the thread is killed in the middle of execution.
+         * @type {boolean}
+         */
+        this.isKilled = false;
+
         /**
          * Target of this thread.
          * @type {?Target}