diff --git a/quickjs-libc.c b/quickjs-libc.c
index 16a22c5..aaca43e 100644
--- a/quickjs-libc.c
+++ b/quickjs-libc.c
@@ -3409,6 +3409,9 @@ static JSValue js_worker_ctor(JSContext *ctx, JSValueConst new_target,
     pthread_attr_init(&attr);
     /* no join at the end */
     pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+    // musl libc gives threads 80 kb stacks, much smaller than
+    // JS_DEFAULT_STACK_SIZE (256 kb)
+    pthread_attr_setstacksize(&attr, 2 << 20); // 2 MB, glibc default
     ret = pthread_create(&tid, &attr, worker_func, args);
     pthread_attr_destroy(&attr);
     if (ret != 0) {
diff --git a/quickjs.c b/quickjs.c
index ecd4e0f..b64a59f 100644
--- a/quickjs.c
+++ b/quickjs.c
@@ -67,7 +67,7 @@
 #define CONFIG_PRINTF_RNDN
 #endif
 
-#if !defined(EMSCRIPTEN) && !defined(__ASAN__)
+#if !defined(EMSCRIPTEN)
 /* enable stack limitation */
 #define CONFIG_STACK_CHECK
 #endif
@@ -1635,6 +1635,9 @@ JSRuntime *JS_NewRuntime2(const JSMallocFunctions *mf, void *opaque)
     rt->js_class_id_alloc = JS_CLASS_INIT_COUNT;
 
     rt->stack_size = JS_DEFAULT_STACK_SIZE;
+#ifdef __ASAN__
+    rt->stack_size *= 2; // stack frames are bigger under AddressSanitizer
+#endif
     JS_UpdateStackTop(rt);
 
     rt->current_exception = JS_NULL;
diff --git a/run-test262.c b/run-test262.c
index cbc2eda..6944dc0 100644
--- a/run-test262.c
+++ b/run-test262.c
@@ -531,6 +531,7 @@ static JSValue js_agent_start(JSContext *ctx, JSValue this_val,
 {
     const char *script;
     Test262Agent *agent;
+    pthread_attr_t attr;
 
     if (JS_GetContextOpaque(ctx) != NULL)
         return JS_ThrowTypeError(ctx, "cannot be called inside an agent");
@@ -545,7 +546,12 @@ static JSValue js_agent_start(JSContext *ctx, JSValue this_val,
     agent->script = strdup(script);
     JS_FreeCString(ctx, script);
     list_add_tail(&agent->link, &agent_list);
-    pthread_create(&agent->tid, NULL, agent_start, agent);
+    pthread_attr_init(&attr);
+    // musl libc gives threads 80 kb stacks, much smaller than
+    // JS_DEFAULT_STACK_SIZE (256 kb)
+    pthread_attr_setstacksize(&attr, 2 << 20); // 2 MB, glibc default
+    pthread_create(&agent->tid, &attr, agent_start, agent);
+    pthread_attr_destroy(&attr);
     return JS_UNDEFINED;
 }