diff --git a/config2.h.in b/config2.h.in
index 9fbd0f69b..5687d35ae 100644
--- a/config2.h.in
+++ b/config2.h.in
@@ -821,6 +821,9 @@
 /* The size of `short', as computed by sizeof. */
 #define SIZEOF_SHORT @SIZEOF_SHORT@
 
+/* The size of `intptr_t`, as computed by sizeof. */
+#define SIZEOF_INTPTR_T @SIZEOF_INTPTR_T@
+
 /* If using the C implementation of alloca, define if you know the
    direction of stack growth for your system; otherwise it will be
    automatically deduced at runtime.
diff --git a/meson.build b/meson.build
index 7977d852b..ff2bea554 100644
--- a/meson.build
+++ b/meson.build
@@ -1148,6 +1148,7 @@ conf_data.set('SIZEOF_INT', compiler.sizeof('int'))
 conf_data.set('SIZEOF_LONG', compiler.sizeof('long'))
 conf_data.set('SIZEOF_LONG_LONG', compiler.sizeof('long long'))
 conf_data.set('SIZEOF_OFF_T', compiler.sizeof('off_t'))
+conf_data.set('SIZEOF_INTPTR_T', compiler.sizeof('intptr_t', prefix: '#include <stdint.h>'))
 
 conf_data.set('CONFIG_GNUTLS_OPENSSL_COMPAT', false)
 
diff --git a/src/ecmascript/quickjs/window.c b/src/ecmascript/quickjs/window.c
index 6f4dd2528..d4a04e701 100644
--- a/src/ecmascript/quickjs/window.c
+++ b/src/ecmascript/quickjs/window.c
@@ -273,7 +273,11 @@ js_window_setInterval(JSContext *ctx, JSValueConst this_val, int argc, JSValueCo
 	if (JS_IsFunction(ctx, func)) {
 		struct ecmascript_timeout *id = ecmascript_set_timeout2q(ctx, func, timeout, timeout);
 
-		return JS_NewInt64(ctx, (int64_t)(id));
+#if SIZEOF_UINTPTR_T == 4
+		return JS_NewInt32(ctx, (intptr_t)(id));
+#else
+		return JS_NewInt64(ctx, (intptr_t)(id));
+#endif
 	}
 
 	if (JS_IsString(func)) {
@@ -288,7 +292,11 @@ js_window_setInterval(JSContext *ctx, JSValueConst this_val, int argc, JSValueCo
 		if (code2) {
 			struct ecmascript_timeout *id = ecmascript_set_timeout(ctx, code2, timeout, timeout);
 
-			return JS_NewInt64(ctx, (int64_t)(id));
+#if SIZEOF_UINTPTR_T == 4
+			return JS_NewInt32(ctx, (intptr_t)(id));
+#else
+			return JS_NewInt64(ctx, (intptr_t)(id));
+#endif
 		}
 	}
 
@@ -325,8 +333,11 @@ js_window_setTimeout(JSContext *ctx, JSValueConst this_val, int argc, JSValueCon
 
 	if (JS_IsFunction(ctx, func)) {
 		struct ecmascript_timeout *id = ecmascript_set_timeout2q(ctx, func, timeout, -1);
-
-		return JS_NewInt64(ctx, (int64_t)(id));
+#if SIZEOF_UINTPTR_T == 4
+		return JS_NewInt32(ctx, (intptr_t)(id));
+#else
+		return JS_NewInt64(ctx, (intptr_t)(id));
+#endif
 	}
 
 	if (JS_IsString(func)) {
@@ -340,8 +351,11 @@ js_window_setTimeout(JSContext *ctx, JSValueConst this_val, int argc, JSValueCon
 
 		if (code2) {
 			struct ecmascript_timeout *id = ecmascript_set_timeout(ctx, code2, timeout, -1);
-
-			return JS_NewInt64(ctx, (int64_t)(id));
+#if SIZEOF_UINTPTR_T == 4
+			return JS_NewInt32(ctx, (intptr_t)(id));
+#else
+			return JS_NewInt64(ctx, (intptr_t)(id));
+#endif
 		}
 	}
 
@@ -360,12 +374,17 @@ js_window_clearInterval(JSContext *ctx, JSValueConst this_val, int argc, JSValue
 	if (argc != 1) {
 		return JS_UNDEFINED;
 	}
-	int64_t number;
+	intptr_t number;
 
+#if SIZEOF_UINTPTR_T == 4
+	if (JS_ToInt32(ctx, &number, argv[0])) {
+		return JS_UNDEFINED;
+	}
+#else
 	if (JS_ToInt64(ctx, &number, argv[0])) {
 		return JS_UNDEFINED;
 	}
-
+#endif
 	struct ecmascript_timeout *t = (struct ecmascript_timeout *)(number);
 
 	if (t && found_in_map_timer(t->tid)) {
@@ -391,11 +410,17 @@ js_window_clearTimeout(JSContext *ctx, JSValueConst this_val, int argc, JSValueC
 	if (argc != 1) {
 		return JS_UNDEFINED;
 	}
-	int64_t number;
+	intptr_t number;
 
+#if SIZEOF_UINTPTR_T == 4
+	if (JS_ToInt32(ctx, &number, argv[0])) {
+		return JS_UNDEFINED;
+	}
+#else
 	if (JS_ToInt64(ctx, &number, argv[0])) {
 		return JS_UNDEFINED;
 	}
+#endif
 	struct ecmascript_timeout *t = (struct ecmascript_timeout *)(number);
 
 	if (t && found_in_map_timer(t->tid)) {