diff --git a/src/glob.ts b/src/glob.ts
index ac0c654e..30d4bc3c 100644
--- a/src/glob.ts
+++ b/src/glob.ts
@@ -101,10 +101,10 @@ export interface GlobOptions {
   follow?: boolean
 
   /**
-   * string or string[], or an object with `ignored` and `childrenIgnored`
+   * string or readonly string[], or an object with `ignored` and `childrenIgnored`
    * methods.
    *
-   * If a string or string[] is provided, then this is treated as a glob
+   * If a string or readonly string[] is provided, then this is treated as a glob
    * pattern or array of glob patterns to exclude from matches. To ignore all
    * children within a directory, as well as the entry itself, append `'/**'`
    * to the ignore pattern.
@@ -117,7 +117,7 @@ export interface GlobOptions {
    * determine whether any Path is a match or if its children should be
    * traversed, respectively.
    */
-  ignore?: string | string[] | IgnoreLike
+  ignore?: string | readonly string[] | IgnoreLike
 
   /**
    * Treat brace expansion like `{a,b}` as a "magic" pattern. Has no
@@ -389,7 +389,7 @@ export class Glob<Opts extends GlobOptions> implements GlobOptions {
   dot: boolean
   dotRelative: boolean
   follow: boolean
-  ignore?: string | string[] | IgnoreLike
+  ignore?: string | readonly string[] | IgnoreLike
   magicalBraces: boolean
   mark?: boolean
   matchBase: boolean
diff --git a/src/ignore.ts b/src/ignore.ts
index 583c67f5..b26ed588 100644
--- a/src/ignore.ts
+++ b/src/ignore.ts
@@ -36,7 +36,7 @@ export class Ignore implements IgnoreLike {
   mmopts: MinimatchOptions
 
   constructor(
-    ignored: string[],
+    ignored: readonly string[],
     {
       nobrace,
       nocase,
diff --git a/src/walker.ts b/src/walker.ts
index c70e38bb..758b0e50 100644
--- a/src/walker.ts
+++ b/src/walker.ts
@@ -24,7 +24,7 @@ export interface GlobWalkerOpts {
   dot?: boolean
   dotRelative?: boolean
   follow?: boolean
-  ignore?: string | string[] | IgnoreLike
+  ignore?: string | readonly string[] | IgnoreLike
   mark?: boolean
   matchBase?: boolean
   // Note: maxDepth here means "maximum actual Path.depth()",
@@ -74,12 +74,12 @@ export type MatchStream<O extends GlobWalkerOpts> = Minipass<
 >
 
 const makeIgnore = (
-  ignore: string | string[] | IgnoreLike,
+  ignore: string | readonly string[] | IgnoreLike,
   opts: GlobWalkerOpts,
 ): IgnoreLike =>
   typeof ignore === 'string' ? new Ignore([ignore], opts)
   : Array.isArray(ignore) ? new Ignore(ignore, opts)
-  : ignore
+  : (ignore as IgnoreLike)
 
 /**
  * basic walking utilities that all the glob walker types use
diff --git a/test/ignore.ts b/test/ignore.ts
index 460117b0..3f1a8448 100644
--- a/test/ignore.ts
+++ b/test/ignore.ts
@@ -376,6 +376,24 @@ for (const c of cases) {
   })
 }
 
+t.test('readonly ignore patterns', async t => {
+  const ignore = ['b'] as const
+  const options: GlobOptions = { cwd: 'a', ignore }
+  const expect = j([
+    'abcdef',
+    'abcfed',
+    'bc',
+    'c',
+    'cb',
+    'symlink',
+    'x',
+    'z',
+  ])
+
+  t.same((await glob('*', options)).sort(), expect)
+  t.same(glob.globSync('*', options).sort(), expect)
+})
+
 t.test('race condition', async t => {
   process.chdir(__dirname)
   var pattern = 'fixtures/*'