diff --git a/js/src/jit-test/tests/basic/evalInWorker-interrupt.js b/js/src/jit-test/tests/basic/evalInWorker-interrupt.js
new file mode 100644
index 000000000000..f4ec3b83114f
--- /dev/null
+++ b/js/src/jit-test/tests/basic/evalInWorker-interrupt.js
@@ -0,0 +1,3 @@
+if (helperThreadCount() === 0)
+    quit();
+evalInWorker("setInterruptCallback(function() {}); timeout(1000);");
diff --git a/js/src/shell/js.cpp b/js/src/shell/js.cpp
index 475bd9ae0243..7b0b8aff6c67 100644
--- a/js/src/shell/js.cpp
+++ b/js/src/shell/js.cpp
@@ -139,7 +139,7 @@ static const double MAX_TIMEOUT_INTERVAL = 1800.0;
 // Per-runtime shell state.
 struct ShellRuntime
 {
-    ShellRuntime();
+    explicit ShellRuntime(JSRuntime* rt);
 
     bool isWorker;
     double timeoutInterval;
@@ -287,12 +287,14 @@ extern JS_EXPORT_API(void)   add_history(char* line);
 } // extern "C"
 #endif
 
-ShellRuntime::ShellRuntime()
+ShellRuntime::ShellRuntime(JSRuntime* rt)
   : isWorker(false),
     timeoutInterval(-1.0),
     serviceInterrupt(false),
     haveInterruptFunc(false),
+    interruptFunc(rt, NullValue()),
     lastWarningEnabled(false),
+    lastWarning(rt, NullValue()),
     watchdogLock(nullptr),
     watchdogWakeup(nullptr),
     watchdogThread(nullptr),
@@ -2771,7 +2773,7 @@ WorkerMain(void* arg)
         return;
     }
 
-    UniquePtr<ShellRuntime> sr = MakeUnique<ShellRuntime>();
+    UniquePtr<ShellRuntime> sr = MakeUnique<ShellRuntime>(rt);
     if (!sr) {
         JS_DestroyRuntime(rt);
         js_delete(input);
@@ -2825,6 +2827,9 @@ WorkerMain(void* arg)
     JS::SetLargeAllocationFailureCallback(rt, nullptr, nullptr);
 
     DestroyContext(cx, false);
+
+    KillWatchdog(rt);
+
     JS_DestroyRuntime(rt);
 
     js_delete(input);
@@ -6994,7 +6999,7 @@ main(int argc, char** argv, char** envp)
     if (!rt)
         return 1;
 
-    UniquePtr<ShellRuntime> sr = MakeUnique<ShellRuntime>();
+    UniquePtr<ShellRuntime> sr = MakeUnique<ShellRuntime>(rt);
     if (!sr)
         return 1;
 
@@ -7006,9 +7011,6 @@ main(int argc, char** argv, char** envp)
     if (!SetRuntimeOptions(rt, op))
         return 1;
 
-    sr->interruptFunc.init(rt, NullValue());
-    sr->lastWarning.init(rt, NullValue());
-
     JS_SetGCParameter(rt, JSGC_MAX_BYTES, 0xffffffff);
 
     size_t availMem = op.getIntOption("available-memory");