diff --git a/types/moo/index.d.ts b/types/moo/index.d.ts
index 9cf67c3299..fa3a59d2ab 100644
--- a/types/moo/index.d.ts
+++ b/types/moo/index.d.ts
@@ -50,7 +50,7 @@ export interface Rule {
     };
 }
 export interface Rules {
-    [x: string]: RegExp | string | string[] | Rule;
+    [x: string]: RegExp | string | string[] | Rule | Rule[];
 }
 
 export interface Lexer {
diff --git a/types/moo/moo-tests.ts b/types/moo/moo-tests.ts
index 6f0c18ae2d..c82bedd219 100644
--- a/types/moo/moo-tests.ts
+++ b/types/moo/moo-tests.ts
@@ -75,3 +75,13 @@ lexer.next();
 lexer.next();
 lexer.reset('a different line\n', info);
 lexer.next();
+
+// Transform: https://github.com/no-context/moo#transform
+moo.compile({
+    STRING: [
+        { match: /"""[^]*?"""/, lineBreaks: true, value: x => x.slice(3, -3) },
+        { match: /"(?:\\["\\rn]|[^"\\])*?"/, lineBreaks: true, value: x => x.slice(1, -1) },
+        { match: /'(?:\\['\\rn]|[^'\\])*?'/, lineBreaks: true, value: x => x.slice(1, -1) },
+    ],
+    // ...
+});