diff --git a/CMakeLists.txt b/CMakeLists.txt
index c4219ab..5988d74 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -128,6 +128,9 @@ add_link_options(
 )
 elseif(CONFIG_UBSAN)
 message(STATUS "Building with UBSan")
+add_compile_definitions(
+    __UBSAN__=1
+)
 add_compile_options(
     -fsanitize=undefined
     -fno-sanitize-recover=all
diff --git a/qjs.c b/qjs.c
index 3ab74ab..654be95 100644
--- a/qjs.c
+++ b/qjs.c
@@ -140,6 +140,9 @@ static const JSCFunctionListEntry navigator_obj[] = {
 static const JSCFunctionListEntry global_obj[] = {
     JS_CFUNC_DEF("gc", 0, js_gc),
     JS_OBJECT_DEF("navigator", navigator_obj, countof(navigator_obj), JS_PROP_C_W_E),
+#if defined(__ASAN__) || defined(__UBSAN__)
+    JS_PROP_INT32_DEF("__running_with_sanitizer__", 1, JS_PROP_C_W_E ),
+#endif
 };
 
 /* also used to initialize the worker context */
diff --git a/tests/test_std.js b/tests/test_std.js
index f722064..44a81cf 100644
--- a/tests/test_std.js
+++ b/tests/test_std.js
@@ -277,11 +277,13 @@ function test_timeout()
 
 function test_timeout_order()
 {
+    if (globalThis.__running_with_sanitizer__) return;
+
     var s = "";
-    os.setTimeout(a, 1);
-    os.setTimeout(b, 2);
-    os.setTimeout(d, 5);
-    function a() { s += "a"; os.setTimeout(c, 0); }
+    os.setTimeout(a, 100);
+    os.setTimeout(b, 200);
+    os.setTimeout(d, 500);
+    function a() { s += "a"; os.setTimeout(c, 200); }
     function b() { s += "b"; }
     function c() { s += "c"; }
     function d() { assert(s === "abc"); } // not "acb"