diff --git a/package.json b/package.json
index f8f76ad..15e935d 100644
--- a/package.json
+++ b/package.json
@@ -30,7 +30,7 @@
   },
   "homepage": "https://github.com/patractlabs/as-scale-codec",
   "dependencies": {
-    "as-bignum": "0.2.18"
+    "as-bignum": "0.2.20"
   },
   "devDependencies": {
     "@as-pect/assembly": "6.2.0",
diff --git a/yarn.lock b/yarn.lock
index f898e32..54c343b 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -328,10 +328,10 @@ array-union@^2.1.0:
   resolved "https://registry.yarnpkg.com/array-union/-/array-union-2.1.0.tgz#b798420adbeb1de828d84acd8a2e23d3efe85e8d"
   integrity sha512-HGyxoOTYUyCM6stUe6EJgnd4EoewAI7zMdfqO+kGjnlZmBDz/cR5pf8r/cR4Wq60sL/p0IkcjUEEPwS3GFrIyw==
 
-as-bignum@0.2.18:
-  version "0.2.18"
-  resolved "https://registry.yarnpkg.com/as-bignum/-/as-bignum-0.2.18.tgz#61ed4dd07d4a62107bde227fdb4370190217bf0b"
-  integrity sha512-5LODrOr7wvS643oh7PHfyRtbBO9vCcU69vNNvrqh5yovrApM9nRHDeT5XcqnaSI8TqK9ZhN12qhZnq4rdIGcwQ==
+as-bignum@0.2.20:
+  version "0.2.20"
+  resolved "https://registry.yarnpkg.com/as-bignum/-/as-bignum-0.2.20.tgz#da43785539f4fbaab4c9be0419b8d96a6a5603d8"
+  integrity sha512-X1f6Wt7m/vkA85xLJHWwBgj+20Nyf9sK9Mh8Rkvet5t1TgcImYFpb0PwuhcTb1H8gc35oX3q4adIHrzOT95g8A==
 
 assemblyscript@0.19:
   version "0.19.14"