diff --git a/packages/web3-wrapper/CHANGELOG.json b/packages/web3-wrapper/CHANGELOG.json
index edb4f740b3..3f0339e941 100644
--- a/packages/web3-wrapper/CHANGELOG.json
+++ b/packages/web3-wrapper/CHANGELOG.json
@@ -1,4 +1,13 @@
 [
+    {
+        "version": "6.0.9",
+        "changes": [
+            {
+                "note": "Let `toBaseUnitAmount()` accept a `number`",
+                "pr": 1819
+            }
+        ]
+    },
     {
         "version": "6.0.8",
         "changes": [
diff --git a/packages/web3-wrapper/src/web3_wrapper.ts b/packages/web3-wrapper/src/web3_wrapper.ts
index 16b6b7b6c8..6b8c0f363d 100644
--- a/packages/web3-wrapper/src/web3_wrapper.ts
+++ b/packages/web3-wrapper/src/web3_wrapper.ts
@@ -88,14 +88,13 @@ export class Web3Wrapper {
      * @param   decimals    The number of decimal places the unit amount has.
      * @return  The amount in baseUnits.
      */
-    public static toBaseUnitAmount(amount: BigNumber, decimals: number): BigNumber {
-        assert.isBigNumber('amount', amount);
+    public static toBaseUnitAmount(amount: BigNumber | number, decimals: number): BigNumber {
         assert.isNumber('decimals', decimals);
         const unit = new BigNumber(BASE_TEN).pow(decimals);
-        const baseUnitAmount = amount.times(unit);
+        const baseUnitAmount = unit.times(amount);
         const hasDecimals = baseUnitAmount.decimalPlaces() !== 0;
         if (hasDecimals) {
-            throw new Error(`Invalid unit amount: ${amount.toString()} - Too many decimal places`);
+            throw new Error(`Invalid unit amount: ${amount.toString(BASE_TEN)} - Too many decimal places`);
         }
         return baseUnitAmount;
     }