diff --git a/include/internal.h b/include/internal.h
index 2ecf986..a865d02 100644
--- a/include/internal.h
+++ b/include/internal.h
@@ -247,6 +247,11 @@ static inline bool is_empty_slot(ant_value_t v) {
   return v == T_EMPTY; 
 }
 
+static inline bool is_callable(ant_value_t v) {
+  uint8_t t = vtype(v);
+  return t == T_FUNC || t == T_CFUNC;
+}
+
 bool is_internal_prop(const char *key, ant_offset_t klen);
 size_t uint_to_str(char *buf, size_t bufsize, uint64_t val);
 
diff --git a/src/ant.c b/src/ant.c
index 7e7b141..46bfcb4 100644
--- a/src/ant.c
+++ b/src/ant.c
@@ -6393,11 +6393,6 @@ static ant_value_t builtin_object_toLocaleString(ant_t *js, ant_value_t *args, i
   return js_call_toString(js, js->this_val);
 }
 
-static inline bool is_callable(ant_value_t v) {
-  uint8_t t = vtype(v);
-  return t == T_FUNC || t == T_CFUNC;
-}
-
 static inline ant_value_t require_callback(ant_t *js, ant_value_t *args, int nargs, const char *name) {
   if (nargs == 0 || !is_callable(args[0]))
     return js_mkerr(js, "%s requires a function argument", name);
diff --git a/src/modules/async_hooks.c b/src/modules/async_hooks.c
index 12a0c06..fadb14b 100644
--- a/src/modules/async_hooks.c
+++ b/src/modules/async_hooks.c
@@ -11,11 +11,6 @@
 #include "modules/async_hooks.h"
 #include "modules/symbol.h"
 
-static inline bool async_hooks_is_callable(ant_value_t v) {
-  uint8_t t = vtype(v);
-  return t == T_FUNC || t == T_CFUNC;
-}
-
 static ant_value_t async_hooks_call_with_tail_args(
   ant_t *js, ant_value_t fn, ant_value_t this_arg, ant_value_t *args, int nargs, int start_idx
 ) {
@@ -32,7 +27,7 @@ static ant_value_t async_hooks_call_with_tail_args(
 }
 
 static ant_value_t async_local_storage_run(ant_t *js, ant_value_t *args, int nargs) {
-  if (nargs < 2 || !async_hooks_is_callable(args[1])) {
+  if (nargs < 2 || !is_callable(args[1])) {
     return js_mkerr(js, "AsyncLocalStorage.run(store, callback, ...args) requires a callback");
   }
 
@@ -49,7 +44,7 @@ static ant_value_t async_local_storage_run(ant_t *js, ant_value_t *args, int nar
 }
 
 static ant_value_t async_local_storage_exit(ant_t *js, ant_value_t *args, int nargs) {
-  if (nargs < 1 || !async_hooks_is_callable(args[0])) {
+  if (nargs < 1 || !is_callable(args[0])) {
     return js_mkerr(js, "AsyncLocalStorage.exit(callback, ...args) requires a callback");
   }
 
@@ -89,7 +84,7 @@ static ant_value_t async_local_storage_disable(ant_t *js, ant_value_t *args, int
 }
 
 static ant_value_t async_resource_runInAsyncScope(ant_t *js, ant_value_t *args, int nargs) {
-  if (nargs < 1 || !async_hooks_is_callable(args[0])) {
+  if (nargs < 1 || !is_callable(args[0])) {
     return js_mkerr(js, "AsyncResource.runInAsyncScope(fn[, thisArg, ...args]) requires a function");
   }
   ant_value_t this_arg = nargs > 1 ? args[1] : js_mkundef();
diff --git a/src/modules/napi.c b/src/modules/napi.c
index a7ec86f..e337501 100644
--- a/src/modules/napi.c
+++ b/src/modules/napi.c
@@ -226,11 +226,6 @@ napi_env ant_napi_get_env(ant_t *js) {
   return (napi_env)napi_get_or_create_env(js);
 }
 
-static inline bool napi_is_callable(ant_value_t v) {
-  uint8_t t = vtype(v);
-  return t == T_FUNC || t == T_CFUNC;
-}
-
 static void napi_mark_pending_exception(napi_env env, napi_value exception) {
   ant_napi_env_t *nenv = (ant_napi_env_t *)env;
   if (!nenv) return;
@@ -499,7 +494,7 @@ static void napi_tsfn_async_cb(uv_async_t *handle) {
     ant_value_t cb = tsfn->func_val;
     if (tsfn->call_js_cb) {
       tsfn->call_js_cb((napi_env)tsfn->env, (napi_value)cb, tsfn->context, item->data);
-    } else if (napi_is_callable(cb)) {
+    } else if (is_callable(cb)) {
       sv_vm_call(js->vm, js, cb, js_mkundef(), NULL, 0, NULL, false);
     }
 
@@ -629,7 +624,7 @@ ant_value_t napi_load_native_module(ant_t *js, const char *module_path, ant_valu
   ant_value_t process_obj = js_get(js, js_glob(js), "process");
   ant_value_t dlopen_fn = is_object_type(process_obj) ? js_get(js, process_obj, "dlopen") : js_mkundef();
 
-  if (napi_is_callable(dlopen_fn)) {
+  if (is_callable(dlopen_fn)) {
     ant_value_t argv[2] = {module_obj, js_mkstr(js, module_path, strlen(module_path))};
     ant_value_t dl_res = sv_vm_call(js->vm, js, dlopen_fn, process_obj, argv, 2, NULL, false);
     if (is_err(dl_res) || js->thrown_exists) return js_throw(js, js->thrown_value);
@@ -1973,7 +1968,7 @@ NAPI_EXTERN napi_status NAPI_CDECL napi_call_function(
   napi_value *result
 ) {
   ant_napi_env_t *nenv = (ant_napi_env_t *)env;
-  if (!nenv || !nenv->js || !napi_is_callable((ant_value_t)func)) {
+  if (!nenv || !nenv->js || !is_callable((ant_value_t)func)) {
     return napi_set_last(env, napi_invalid_arg, "invalid argument");
   }
 
@@ -2001,7 +1996,7 @@ NAPI_EXTERN napi_status NAPI_CDECL napi_new_instance(
   napi_value *result
 ) {
   ant_napi_env_t *nenv = (ant_napi_env_t *)env;
-  if (!nenv || !nenv->js || !result || !napi_is_callable((ant_value_t)constructor)) {
+  if (!nenv || !nenv->js || !result || !is_callable((ant_value_t)constructor)) {
     return napi_set_last(env, napi_invalid_arg, "invalid argument");
   }
 
@@ -2065,7 +2060,7 @@ NAPI_EXTERN napi_status NAPI_CDECL napi_coerce_to_object(
   }
 
   ant_value_t obj_ctor = js_get(nenv->js, js_glob(nenv->js), "Object");
-  if (!napi_is_callable(obj_ctor)) return napi_set_last(env, napi_generic_failure, "Object constructor missing");
+  if (!is_callable(obj_ctor)) return napi_set_last(env, napi_generic_failure, "Object constructor missing");
   ant_value_t arg = (ant_value_t)value;
   ant_value_t out = sv_vm_call(nenv->js->vm, nenv->js, obj_ctor, js_mkundef(), &arg, 1, NULL, false);
   if (is_err(out) || nenv->js->thrown_exists) return napi_check_pending_from_result(env, out);
diff --git a/src/modules/observable.c b/src/modules/observable.c
index 07e79e9..1d535cf 100644
--- a/src/modules/observable.c
+++ b/src/modules/observable.c
@@ -11,10 +11,7 @@
 #include "modules/symbol.h"
 #include "modules/observable.h"
 
-static inline bool is_callable(ant_value_t val) {
-  uint8_t t = vtype(val);
-  return t == T_FUNC || t == T_CFUNC;
-}
+
 
 static bool subscription_closed(ant_t *js, ant_value_t subscription) {
   ant_value_t observer = js_get_slot(subscription, SLOT_SUBSCRIPTION_OBSERVER);
diff --git a/src/modules/tty.c b/src/modules/tty.c
index 49fcbcc..2f20335 100644
--- a/src/modules/tty.c
+++ b/src/modules/tty.c
@@ -37,10 +37,7 @@
 #include "modules/symbol.h"
 #include "modules/tty.h"
 
-static inline bool is_callable(ant_value_t value) {
-  uint8_t t = vtype(value);
-  return t == T_FUNC || t == T_CFUNC;
-}
+
 
 static bool parse_fd(ant_value_t value, int *fd_out) {
   int fd = 0;
diff --git a/src/modules/util.c b/src/modules/util.c
index 64e11ea..0702f51 100644
--- a/src/modules/util.c
+++ b/src/modules/util.c
@@ -56,11 +56,6 @@ static const util_style_entry_t util_styles[] = {
   {"bgWhite", "\x1b[47m", "\x1b[49m"},
 };
 
-static inline bool util_is_callable(ant_value_t v) {
-  uint8_t t = vtype(v);
-  return t == T_FUNC || t == T_CFUNC;
-}
-
 static bool util_sb_reserve(util_sb_t *sb, size_t extra) {
   size_t need = sb->len + extra + 1;
   if (need <= sb->cap) return true;
@@ -348,7 +343,7 @@ static ant_value_t util_promisify_callback(ant_t *js, ant_value_t *args, int nar
 static ant_value_t util_promisified_call(ant_t *js, ant_value_t *args, int nargs) {
   ant_value_t fn = js_getcurrentfunc(js);
   ant_value_t original = js_get_slot(fn, SLOT_DATA);
-  if (!util_is_callable(original)) return js_mkerr(js, "promisified target is not callable");
+  if (!is_callable(original)) return js_mkerr(js, "promisified target is not callable");
 
   ant_value_t promise = js_mkpromise(js);
   ant_value_t ctx = js_mkobj(js);
@@ -385,7 +380,7 @@ static ant_value_t util_promisified_call(ant_t *js, ant_value_t *args, int nargs
 }
 
 static ant_value_t util_promisify(ant_t *js, ant_value_t *args, int nargs) {
-  if (nargs < 1 || !util_is_callable(args[0])) {
+  if (nargs < 1 || !is_callable(args[0])) {
     return js_mkerr(js, "promisify(fn) requires a function");
   }
   return js_heavy_mkfun(js, util_promisified_call, args[0]);
diff --git a/src/modules/worker_threads.c b/src/modules/worker_threads.c
index 29abc8a..ae2044a 100644
--- a/src/modules/worker_threads.c
+++ b/src/modules/worker_threads.c
@@ -61,11 +61,6 @@ typedef struct ant_worker_thread {
 
 static ant_worker_thread_t *active_workers_head = NULL;
 
-static inline bool wt_is_callable(ant_value_t v) {
-  uint8_t t = vtype(v);
-  return t == T_FUNC || t == T_CFUNC;
-}
-
 static bool wt_is_worker_mode(void) {
   const char *mode = getenv(WT_ENV_MODE);
   return mode && strcmp(mode, "1") == 0;
@@ -181,7 +176,7 @@ static void wt_port_queue_push(ant_t *js, ant_value_t port, ant_value_t value) {
 }
 
 static void wt_port_call_listener(ant_t *js, ant_value_t this_obj, ant_value_t fn, ant_value_t arg) {
-  if (!wt_is_callable(fn)) return;
+  if (!is_callable(fn)) return;
   ant_value_t argv[1] = {arg};
   
   sv_vm_call(js->vm, js, fn, this_obj, argv, 1, NULL, false);
@@ -194,8 +189,8 @@ static bool wt_port_should_deliver(ant_t *js, ant_value_t port) {
   ant_value_t once_fn = js_get_slot(port, SLOT_WT_PORT_ONCE_MESSAGE);
   ant_value_t onmessage = js_get(js, port, "onmessage");
 
-  bool has_event_listener = wt_is_callable(on_fn) || wt_is_callable(once_fn);
-  if (wt_is_callable(onmessage)) return true;
+  bool has_event_listener = is_callable(on_fn) || is_callable(once_fn);
+  if (is_callable(onmessage)) return true;
   return started && has_event_listener;
 }
 
@@ -210,13 +205,13 @@ static void wt_port_drain(ant_t *js, ant_value_t port) {
     wt_port_call_listener(js, port, on_fn, msg);
 
     ant_value_t once_fn = js_get_slot(port, SLOT_WT_PORT_ONCE_MESSAGE);
-    if (wt_is_callable(once_fn)) {
+    if (is_callable(once_fn)) {
       wt_port_call_listener(js, port, once_fn, msg);
       js_set_slot(port, SLOT_WT_PORT_ONCE_MESSAGE, js_mkundef());
     }
 
     ant_value_t onmessage = js_get(js, port, "onmessage");
-    if (wt_is_callable(onmessage)) {
+    if (is_callable(onmessage)) {
       ant_value_t event_obj = js_mkobj(js);
       js_set(js, event_obj, "data", msg);
       wt_port_call_listener(js, port, onmessage, event_obj);
@@ -233,7 +228,7 @@ static ant_value_t wt_make_resolved_promise(ant_t *js, ant_value_t value) {
 }
 
 static void wt_call_listener(ant_t *js, ant_value_t this_obj, ant_value_t fn, ant_value_t arg) {
-  if (!wt_is_callable(fn)) return;
+  if (!is_callable(fn)) return;
   ant_value_t argv[1] = {arg};
 
   sv_vm_call(js->vm, js, fn, this_obj, argv, 1, NULL, false);
@@ -258,7 +253,7 @@ static void wt_emit(ant_worker_thread_t *wt, const char *event, ant_value_t arg)
   wt_call_listener(js, this_obj, on_fn, arg);
 
   ant_value_t once_fn = js_get_slot(this_obj, once_slot);
-  if (wt_is_callable(once_fn)) {
+  if (is_callable(once_fn)) {
     wt_call_listener(js, this_obj, once_fn, arg);
     js_set_slot(this_obj, once_slot, js_mkundef());
   }
@@ -579,7 +574,7 @@ static int wt_spawn_worker(
 }
 
 static ant_value_t worker_threads_worker_on(ant_t *js, ant_value_t *args, int nargs) {
-  if (nargs < 2 || vtype(args[0]) != T_STR || !wt_is_callable(args[1])) {
+  if (nargs < 2 || vtype(args[0]) != T_STR || !is_callable(args[1])) {
     return js_mkerr(js, "Worker.on(event, listener) requires (string, function)");
   }
 
@@ -600,7 +595,7 @@ static ant_value_t worker_threads_worker_on(ant_t *js, ant_value_t *args, int na
 }
 
 static ant_value_t worker_threads_worker_once(ant_t *js, ant_value_t *args, int nargs) {
-  if (nargs < 2 || vtype(args[0]) != T_STR || !wt_is_callable(args[1])) {
+  if (nargs < 2 || vtype(args[0]) != T_STR || !is_callable(args[1])) {
     return js_mkerr(js, "Worker.once(event, listener) requires (string, function)");
   }
 
@@ -688,7 +683,7 @@ static ant_value_t worker_threads_message_port_post_message(ant_t *js, ant_value
 }
 
 static ant_value_t worker_threads_message_port_on(ant_t *js, ant_value_t *args, int nargs) {
-  if (nargs < 2 || vtype(args[0]) != T_STR || !wt_is_callable(args[1])) {
+  if (nargs < 2 || vtype(args[0]) != T_STR || !is_callable(args[1])) {
     return js_mkerr(js, "MessagePort.on(event, listener) requires (string, function)");
   }
   ant_value_t this_obj = js_getthis(js);
@@ -706,7 +701,7 @@ static ant_value_t worker_threads_message_port_on(ant_t *js, ant_value_t *args,
 }
 
 static ant_value_t worker_threads_message_port_once(ant_t *js, ant_value_t *args, int nargs) {
-  if (nargs < 2 || vtype(args[0]) != T_STR || !wt_is_callable(args[1])) {
+  if (nargs < 2 || vtype(args[0]) != T_STR || !is_callable(args[1])) {
     return js_mkerr(js, "MessagePort.once(event, listener) requires (string, function)");
   }
   ant_value_t this_obj = js_getthis(js);