diff --git a/src/main/ts/util.ts b/src/main/ts/util.ts
index f93c448..b242883 100644
--- a/src/main/ts/util.ts
+++ b/src/main/ts/util.ts
@@ -22,7 +22,14 @@ export const makeDeferred = <T = any, E = any>(): { promise: Promise<T>, resolve
 
 export const isPromiseLike = (value: any): boolean => typeof value?.then === 'function'
 
-export const isStringLiteral = (pieces: any) => pieces?.every?.((p: any) => typeof p === 'string')
+export const isStringLiteral = (
+  pieces: any,
+  ...rest: any[]
+): pieces is TemplateStringsArray =>
+  pieces?.length > 0 &&
+  pieces.raw?.length === pieces.length &&
+  Object.isFrozen(pieces) &&
+  rest.length + 1 === pieces.length
 
 export const assign = <T, E>(target: T, ...extras: E[]): T =>
   Object.defineProperties(target, extras.reduce<Record<string, any>>((m: any, extra) =>
diff --git a/src/main/ts/x.ts b/src/main/ts/x.ts
index 4328397..c8aa41b 100644
--- a/src/main/ts/x.ts
+++ b/src/main/ts/x.ts
@@ -93,7 +93,7 @@ export const $: TShell = function(this: any, pieces?: any, ...args: any): any {
 
   if (pieces === undefined) return applyMixins($, preset)
 
-  if (isStringLiteral(pieces)) return ignite(preset, pieces, ...args)
+  if (isStringLiteral(pieces, ...args)) return ignite(preset, pieces, ...args)
 
   return (...args: any) => $.apply(self ? assign(self, pieces) : pieces, args)
 }
diff --git a/src/test/ts/util.test.ts b/src/test/ts/util.test.ts
index d71bd4e..94df44d 100644
--- a/src/test/ts/util.test.ts
+++ b/src/test/ts/util.test.ts
@@ -1,10 +1,21 @@
 import * as assert from 'node:assert'
-import { describe, it } from 'node:test'
-import { assign } from '../../main/ts/util.js'
+import {describe, it, test} from 'node:test'
+import { assign, isStringLiteral } from '../../main/ts/util.js'
 
 describe('util', () => {
   it('assign()', () => {
     assert.deepEqual(assign({a: 1}, {b: 2}), {a: 1, b: 2})
     assert.deepEqual(assign({a: 1}, {a: undefined}), {a: 1})
   })
+
+  test('isStringLiteral()', () => {
+    const bar = 'baz'
+    assert.ok(isStringLiteral``)
+    assert.ok(isStringLiteral`foo`)
+    assert.ok(isStringLiteral`foo ${bar}`)
+
+    assert.ok(!isStringLiteral(''))
+    assert.ok(!isStringLiteral('foo'))
+    assert.ok(!isStringLiteral(['foo']))
+  })
 })