diff --git a/gulp-utils.js b/gulp-utils.js
index d859efc9..c6ecffe7 100644
--- a/gulp-utils.js
+++ b/gulp-utils.js
@@ -57,6 +57,7 @@ function getAsc() {
             "assembly/near.ts" : "./node_modules/near-runtime-ts/near.ts",
             "assembly/json/encoder.ts" : "./node_modules/assemblyscript-json/assembly/encoder.ts",
             "assembly/json/decoder.ts" : "./node_modules/assemblyscript-json/assembly/decoder.ts",
+            "bignum/integer/u128.ts" : "./node_modules/bignum/assembly/integer/u128.ts",
           };
           if (path in mapping) {
             path =  mapping[path]