1 files changed, 6 insertions, 0 deletions
diff --git a/src/types.ts b/src/types.ts
index 273389480..f5b0f3e7c 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -30,6 +30,12 @@ export interface ExchangeContract {
     isValidSignature: any;
 }
 
+export interface ERC20Contract {
+    balanceOf: {
+        call: (address: string) => Promise<BigNumber.BigNumber>;
+    };
+}
+
 export interface TokenRegistryContract {
     getTokenMetaData: any;
     getTokenAddresses: any;