diff --git a/CHANGELOG.md b/CHANGELOG.md
index 426b51bac..d8e65310d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@ Changes:
 
 - Use upstream `@substrate/ss58-registry` (instead of duplicating here)
 - Swap `micro-base` to `@scure/base` (same package, audited)
+- Bump `bn.js` library to latest 5.2.0 (has impact on e.g. API)
 - Upgrade dependencies to latest stable versions
 
 
diff --git a/packages/util/package.json b/packages/util/package.json
index c44b61d08..046bc9bb8 100644
--- a/packages/util/package.json
+++ b/packages/util/package.json
@@ -42,8 +42,8 @@
     "@polkadot/x-global": "8.3.4-6",
     "@polkadot/x-textdecoder": "8.3.4-6",
     "@polkadot/x-textencoder": "8.3.4-6",
-    "@types/bn.js": "^4.11.6",
-    "bn.js": "^4.12.0",
+    "@types/bn.js": "^5.1.0",
+    "bn.js": "^5.2.0",
     "ip-regex": "^4.3.0"
   },
   "devDependencies": {
diff --git a/packages/util/src/stringify.spec.ts b/packages/util/src/stringify.spec.ts
index a3ba5b7f8..b7ae68f27 100644
--- a/packages/util/src/stringify.spec.ts
+++ b/packages/util/src/stringify.spec.ts
@@ -13,19 +13,19 @@ describe('stringify', (): void => {
 
   it('stringifies an array of values', (): void => {
     expect(
-      stringify(['a', 1, 2n, new BN(3)])
-    ).toEqual('["a",1,"2","3"]');
+      stringify(['a', 1, 2n, new BN(69)])
+    ).toEqual('["a",1,"2","45"]');
   });
 
   it('stringifies an array of values (with spaces)', (): void => {
     expect(
       stringify(['a', 1, 2n, new BN(3)], 2)
-    ).toEqual('[\n  "a",\n  1,\n  "2",\n  "3"\n]');
+    ).toEqual('[\n  "a",\n  1,\n  "2",\n  "03"\n]');
   });
 
   it('stringifies a nested object', (): void => {
     expect(
       stringify({ a: 'a', b: 1, c: { d: 2n, e: new BN(3) } })
-    ).toEqual('{"a":"a","b":1,"c":{"d":"2","e":"3"}}');
+    ).toEqual('{"a":"a","b":1,"c":{"d":"2","e":"03"}}');
   });
 });
diff --git a/yarn.lock b/yarn.lock
index b76795171..e37dfd1e7 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2168,8 +2168,8 @@ __metadata:
     "@polkadot/x-randomvalues": 8.3.4-6
     "@polkadot/x-textdecoder": 8.3.4-6
     "@polkadot/x-textencoder": 8.3.4-6
-    "@types/bn.js": ^4.11.6
-    bn.js: ^4.12.0
+    "@types/bn.js": ^5.1.0
+    bn.js: ^5.2.0
     ip-regex: ^4.3.0
   languageName: unknown
   linkType: soft
@@ -2467,12 +2467,12 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@types/bn.js@npm:^4.11.6":
-  version: 4.11.6
-  resolution: "@types/bn.js@npm:4.11.6"
+"@types/bn.js@npm:^5.1.0":
+  version: 5.1.0
+  resolution: "@types/bn.js@npm:5.1.0"
   dependencies:
     "@types/node": "*"
-  checksum: 7f66f2c7b7b9303b3205a57184261974b114495736b77853af5b18d857c0b33e82ce7146911e86e87a87837de8acae28986716fd381ac7c301fd6e8d8b6c811f
+  checksum: 1dc1cbbd7a1e8bf3614752e9602f558762a901031f499f3055828b5e3e2bba16e5b88c27b3c4152ad795248fbe4086c731a5c4b0f29bb243f1875beeeabee59c
   languageName: node
   linkType: hard
 
@@ -3492,14 +3492,14 @@ __metadata:
   languageName: node
   linkType: hard
 
-"bn.js@npm:^4.11.8, bn.js@npm:^4.11.9, bn.js@npm:^4.12.0":
+"bn.js@npm:^4.11.8, bn.js@npm:^4.11.9":
   version: 4.12.0
   resolution: "bn.js@npm:4.12.0"
   checksum: 39afb4f15f4ea537b55eaf1446c896af28ac948fdcf47171961475724d1bb65118cca49fa6e3d67706e4790955ec0e74de584e45c8f1ef89f46c812bee5b5a12
   languageName: node
   linkType: hard
 
-"bn.js@npm:^5.1.1":
+"bn.js@npm:^5.1.1, bn.js@npm:^5.2.0":
   version: 5.2.0
   resolution: "bn.js@npm:5.2.0"
   checksum: 6117170393200f68b35a061ecbf55d01dd989302e7b3c798a3012354fa638d124f0b2f79e63f77be5556be80322a09c40339eda6413ba7468524c0b6d4b4cb7a