diff --git a/main/helper/lookup-helper.ts b/main/helper/lookup-helper.ts
index 9321975..4288473 100644
--- a/main/helper/lookup-helper.ts
+++ b/main/helper/lookup-helper.ts
@@ -5,7 +5,7 @@ export function getLookup<T, C extends ConstructorFunction<T>, U extends LookupT
     lookupType: U,
 ): FunctionCallLookup<T, C, U> {
     switch (lookupType) {
-        case 'constructor':
+        case 'constructorFunction':
             return mock.constructorCallLookup as FunctionCallLookup<T, C, U>;
         case 'function':
             return mock.functionCallLookup as FunctionCallLookup<T, C, U>;
diff --git a/main/mock/contracts.ts b/main/mock/contracts.ts
index 024bf07..76a6110 100644
--- a/main/mock/contracts.ts
+++ b/main/mock/contracts.ts
@@ -50,7 +50,7 @@ export type LookupParams<
     C extends ConstructorFunction<T>,
     U extends LookupType,
     K extends FunctionName<T, C, U>,
-> = U extends 'constructor'
+> = U extends 'constructorFunction'
     ? ConstructorParams<C>
     : U extends FunctionTypes
     ? FunctionParams<LookupFunction<T, C, U, K>>
@@ -75,10 +75,10 @@ export type InstanceLookupTypes = 'function' | 'getter' | 'setter';
 export type SetterTypes = 'staticSetter' | 'setter';
 export type GetterTypes = 'staticGetter' | 'getter';
 export type FunctionTypes = 'staticFunction' | 'function';
-export type LookupType = StaticLookupTypes | InstanceLookupTypes | 'constructor';
+export type LookupType = StaticLookupTypes | InstanceLookupTypes | 'constructorFunction';
 
-export type VerifierTarget<T, C extends ConstructorFunction<T>, U extends LookupType> = U extends 'constructor'
-    ? { constructor: C }
+export type VerifierTarget<T, C extends ConstructorFunction<T>, U extends LookupType> = U extends 'constructorFunction'
+    ? { constructorFunction: C }
     : U extends StaticLookupTypes
     ? U extends FunctionTypes
         ? FunctionsOnly<C>
@@ -158,7 +158,7 @@ export interface IMocked<T, C extends ConstructorFunction<T> = never> {
      */
     mockConstructor: C;
 
-    constructorCallLookup: FunctionCallLookup<T, C, 'constructor'>;
+    constructorCallLookup: FunctionCallLookup<T, C, 'constructorFunction'>;
     functionCallLookup: FunctionCallLookup<T, C, 'function'>;
     setterCallLookup: FunctionCallLookup<T, C, 'setter'>;
     getterCallLookup: FunctionCallLookup<T, C, 'getter'>;
@@ -182,7 +182,7 @@ export interface IMocked<T, C extends ConstructorFunction<T> = never> {
      */
     setup(...operators: OperatorFunction<T, C>[]): IMocked<T, C>;
 
-    setupConstructor(): IFunctionWithParametersVerification<ConstructorParams<C>, T, 'constructor', C>;
+    setupConstructor(): IFunctionWithParametersVerification<ConstructorParams<C>, T, 'constructorFunction', C>;
 
     /**
      * Sets up a single function and returns a function verifier to verify calls made and parameters passed.
@@ -258,7 +258,7 @@ export interface IMocked<T, C extends ConstructorFunction<T> = never> {
      * expect(myMock.withFunction("functionName")).wasCalledOnce():
      * expect(myMock.withFunction("functionName").withParameters("one", 2)).wasCalledOnce():
      */
-    withConstructor(): IFunctionWithParametersVerification<ConstructorParams<C>, T, 'constructor', C>;
+    withConstructor(): IFunctionWithParametersVerification<ConstructorParams<C>, T, 'constructorFunction', C>;
 
     /**
      * Verifies calls to a previously setup function.
diff --git a/main/mock/operators.ts b/main/mock/operators.ts
index 289ddd0..0a8e2a3 100644
--- a/main/mock/operators.ts
+++ b/main/mock/operators.ts
@@ -24,12 +24,12 @@ import {
  */
 export function setupConstructor<T, C extends ConstructorFunction<T>>(): OperatorFunction<T, C> {
     return (mocked: IMocked<T, C>) => {
-        (mocked.mockConstructor = class MockConstructor {
+        mocked.mockConstructor = class MockConstructor {
             constructor(...args: ConstructorParams<C>) {
                 trackConstructorCall(mocked, args as any);
             }
-        } as C),
-            (mocked.constructorCallLookup['constructor'] = []);
+        } as C;
+        mocked.constructorCallLookup['constructorFunction'] = [];
 
         return mocked;
     };
@@ -266,11 +266,11 @@ function definePropertyImpl<
 
 export function trackConstructorCall<T, C extends ConstructorFunction<T>>(
     mock: IMocked<T, C>,
-    params: LookupParams<T, C, 'constructor', 'constructor'>,
+    params: LookupParams<T, C, 'constructorFunction', 'constructorFunction'>,
 ) {
-    const lookup = getLookup(mock, 'constructor');
+    const lookup = getLookup(mock, 'constructorFunction');
 
-    trackCall(lookup, 'constructor', params);
+    trackCall(lookup, 'constructorFunction', params);
 }
 
 function trackFunctionCall<
diff --git a/main/mock/verifiers.ts b/main/mock/verifiers.ts
index 0fc73ec..cb5acd3 100644
--- a/main/mock/verifiers.ts
+++ b/main/mock/verifiers.ts
@@ -29,9 +29,9 @@ export type VerifierParams<
 
 export function createConstructorParameterVerifier<T, C extends ConstructorFunction<T>>(
     mocked: IMocked<T, C>,
-): IFunctionWithParametersVerification<ConstructorParams<C>, T, 'constructor', C> {
+): IFunctionWithParametersVerification<ConstructorParams<C>, T, 'constructorFunction', C> {
     return {
-        ...createFunctionVerifier(mocked, 'constructor', 'constructor'),
+        ...createFunctionVerifier(mocked, 'constructorFunction', 'constructorFunction'),
         /**
          * withParameters and withParametersEqualTo should have signatures:
          *
@@ -44,9 +44,9 @@ export function createConstructorParameterVerifier<T, C extends ConstructorFunct
          * so we internally type the function as any. This does not affect the extrnal facing function type
          */
         withParameters: ((...parameters: ParameterMatcher<any>[]) =>
-            verifyParameters(parameters, mocked, 'constructor', 'constructor', false)) as any,
+            verifyParameters(parameters, mocked, 'constructorFunction', 'constructorFunction', false)) as any,
         withParametersEqualTo: ((...parameters: ParameterMatcher<any>[]) =>
-            verifyParameters(parameters, mocked, 'constructor', 'constructor', true)) as any,
+            verifyParameters(parameters, mocked, 'constructorFunction', 'constructorFunction', true)) as any,
     };
 }
 
@@ -167,10 +167,16 @@ export function verifyFunctionCalled<T, C extends ConstructorFunction<T>, U exte
     let errorMessageSetupFunction: string;
     let errorMessageDescription: string;
 
-    const functionCalls: LookupParams<T, C, U, any>[] | undefined = getLookup(mock, type)[functionName];
+    const functionCallsLookup = getLookup(mock, type);
+
+    console.log(`functionCallsLookup`, { functionCallsLookup });
+
+    const functionCalls: LookupParams<T, C, U, any>[] | undefined = functionCallsLookup[functionName];
+
+    console.log(`functionCalls`, { functionCalls });
 
     switch (type) {
-        case 'constructor':
+        case 'constructorFunction':
             expectationMessage = `Expected constructor to be called`;
             errorMessageSetupFunction = `Mock.setupConstructor()`;
             errorMessageDescription = `Constructor`;
@@ -213,9 +219,12 @@ export function verifyFunctionCalled<T, C extends ConstructorFunction<T>, U exte
     }
 
     if (functionCalls === undefined) {
-        return createCustomMatcherFailResult(
-            `${errorMessageDescription} "${functionName}" has not been setup. Please setup using ${errorMessageSetupFunction} before verifying calls.`,
-        );
+        const message =
+            type === 'constructorFunction'
+                ? `Constructor has not been setup. Please setup using ${errorMessageSetupFunction} before verifying calls.`
+                : `${errorMessageDescription} "${functionName}" has not been setup. Please setup using ${errorMessageSetupFunction} before verifying calls.`;
+
+        return createCustomMatcherFailResult(message);
     }
 
     const parameterMatchResults = functionCalls.map((params) => matchParameters(params, parameterMatchers));
diff --git a/spec/mock/mock.spec.ts b/spec/mock/mock.spec.ts
index 1ce315d..e4fd98b 100644
--- a/spec/mock/mock.spec.ts
+++ b/spec/mock/mock.spec.ts
@@ -217,6 +217,14 @@ describe('mock', () => {
                 `Property "propertyTwo" has not been setup. Please setup using Mock.setupProperty() before verifying calls.`,
             );
         });
+
+        it('withConstructor will fail with a meaningful error if we try to assert a function that is not setup', () => {
+            verifyFailure(
+                mocked.withConstructor(),
+                matchers.wasNotCalled(),
+                `Constructor has not been setup. Please setup using Mock.setupConstructor() before verifying calls.`,
+            );
+        });
     });
 
     describe('withFunction', () => {