diff --git a/packages/bytes/src.ts/index.ts b/packages/bytes/src.ts/index.ts
index 1872e15cf..f291c5191 100644
--- a/packages/bytes/src.ts/index.ts
+++ b/packages/bytes/src.ts/index.ts
@@ -97,7 +97,7 @@ export function arrayify(value: BytesLike | Hexable | number, options?: DataOpti
         const result = [];
         while (value) {
             result.unshift(value & 0xff);
-            value /= 256;
+            value = parseInt(String(value / 256));
         }
         if (result.length === 0) { result.push(0); }
 
diff --git a/packages/rlp/src.ts/index.ts b/packages/rlp/src.ts/index.ts
index 6fd0dfad6..1f00f1033 100644
--- a/packages/rlp/src.ts/index.ts
+++ b/packages/rlp/src.ts/index.ts
@@ -2,8 +2,7 @@
 
 //See: https://github.com/ethereum/wiki/wiki/RLP
 
-
-import { arrayify, BytesLike, hexlify } from "@ethersproject/bytes";
+import { arrayify, BytesLike, hexlify, isBytesLike } from "@ethersproject/bytes";
 
 function arrayifyInteger(value: number): Array<number> {
     const result = [];
@@ -41,6 +40,10 @@ function _encode(object: Array<any> | string): Array<number> {
 
     }
 
+    if (!isBytesLike(object)) {
+        throw new Error("RLP object must be BytesLike");
+    }
+
     const data: Array<number> = Array.prototype.slice.call(arrayify(object));
 
     if (data.length === 1 && data[0] <= 0x7f) {