diff --git a/src/mock-contract.ts b/src/mock-contract.ts
index 8de72a4..fc9434d 100644
--- a/src/mock-contract.ts
+++ b/src/mock-contract.ts
@@ -3,7 +3,7 @@ import {
   encodeFunctionData,
   encodeFunctionResult,
   PublicClient,
-  toFunctionHash,
+  toFunctionSelector,
   WalletClient,
 } from "viem";
 import {
@@ -48,7 +48,7 @@ export const calculateFnSigHash = (
     | MockWriteCallExpectation<AbiFunction>,
 ) => {
   if (call.inputs === undefined || call.inputs === null) {
-    return toFunctionHash(call.abi);
+    return toFunctionSelector(call.abi);
   }
   return encodeFunctionData({
     abi: [call.abi as AbiFunction],
diff --git a/test/mock-contract.test.ts b/test/mock-contract.test.ts
index 0990bea..49f92e2 100644
--- a/test/mock-contract.test.ts
+++ b/test/mock-contract.test.ts
@@ -122,6 +122,27 @@ describe("Doppelganger", function () {
       }
     });
 
+    it("Should allow undefined call.inputs for read calls", async function () {
+      const [signer] = await hre.viem.getWalletClients();
+      const reader = await hre.viem.getPublicClient();
+
+      const mock = await deployMock(signer, reader);
+      await mock.setup<ExtractAbiFunction<typeof erc20ABI, "balanceOf">>({
+        kind: "read",
+        abi: erc20ABI[0],
+        outputs: [100n],
+      });
+
+      expect(
+        await reader.readContract({
+          address: mock.address,
+          abi: erc20ABI,
+          functionName: "balanceOf",
+          args: [zeroAddress],
+        }),
+      ).to.equal(100n);
+    });
+
     // TODO:
     it.skip("Should allow for the mocking of events", async function () {});
   });