diff --git a/lib/lib.es2018.regexp.d.ts b/lib/lib.es2018.regexp.d.ts
index 0c3358ef6af..a0017f21438 100644
--- a/lib/lib.es2018.regexp.d.ts
+++ b/lib/lib.es2018.regexp.d.ts
@@ -28,4 +28,9 @@ interface RegExpExecArray {
     groups?: {
         [key: string]: string
     }
-}
\ No newline at end of file
+}
+
+interface RegExp {
+    /** Returns a Boolean value indicating the state of the dotAll flag (s) used with a regular expression. Default is false. Read-only. */
+    readonly dotAll: boolean;
+}