Add necessary cast

1 files changed, 2 insertions, 1 deletions

diff --git a/packages/base-contract/src/index.ts b/packages/base-contract/src/index.ts
index a8e4ad2e2..354362d45 100644
--- a/packages/base-contract/src/index.ts
+++ b/packages/base-contract/src/index.ts
@@ -1,5 +1,6 @@
 import { abiUtils, BigNumber } from '@0xproject/utils';
 import { Web3Wrapper } from '@0xproject/web3-wrapper';
+import { FunctionAbi } from 'ethereum-protocol';
 import {
     AbiDefinition,
     AbiType,
@@ -129,7 +130,7 @@ export class BaseContract {
             if (abiDefinition.type !== AbiType.Function) {
                 return false;
             }
-            const abiFunctionSignature = abiUtils.getFunctionSignature(abiDefinition);
+            const abiFunctionSignature = abiUtils.getFunctionSignature(abiDefinition as MethodAbi);
             if (abiFunctionSignature === functionSignature) {
                 return true;
             }