diff --git a/types/xregexp/tsconfig.json b/types/xregexp/tsconfig.json
index 08c3876c26..e1705013ea 100644
--- a/types/xregexp/tsconfig.json
+++ b/types/xregexp/tsconfig.json
@@ -6,7 +6,7 @@
         ],
         "noImplicitAny": true,
         "noImplicitThis": true,
-        "strictNullChecks": false,
+        "strictNullChecks": true,
         "strictFunctionTypes": true,
         "baseUrl": "../",
         "typeRoots": [
@@ -20,4 +20,4 @@
         "index.d.ts",
         "xregexp-tests.ts"
     ]
-}
\ No newline at end of file
+}