diff --git a/src/lib/engine.ts b/src/lib/engine.ts
index fdeea4d..11577fa 100644
--- a/src/lib/engine.ts
+++ b/src/lib/engine.ts
@@ -75,7 +75,7 @@ async function run<ConsequencePayload, C extends Context,
 export const evaluateRules = async <ConsequencePayload, C extends Context,
     RF extends RuleFunctionsTable<C, ConsequencePayload, CustomEngineRuleFuncRunOptions>,
     F extends FunctionsTable<C, CustomEngineRuleFuncRunOptions>,
-    Ignore = never, CustomEngineRuleFuncRunOptions = {}>(rules: Rule<ConsequencePayload,
+    Ignore = never, CustomEngineRuleFuncRunOptions = undefined>(rules: Rule<ConsequencePayload,
       RF, C, F, Ignore, CustomEngineRuleFuncRunOptions>[], context: C, functionsTable: F, ruleFunctionsTable: RF,
  haltOnFirstMatch: boolean, runOptions: CustomEngineRuleFuncRunOptions)
     : Promise<void | ResolvedConsequence<ConsequencePayload>[]> => {
@@ -86,7 +86,7 @@ export const evaluateRules = async <ConsequencePayload, C extends Context,
 export const validateRules = async <ConsequencePayload, C extends Context,
     RF extends RuleFunctionsTable<C, ConsequencePayload, CustomEngineRuleFuncRunOptions>,
     F extends FunctionsTable<C, CustomEngineRuleFuncRunOptions>,
-    Ignore = never, CustomEngineRuleFuncRunOptions = {}>(
+    Ignore = never, CustomEngineRuleFuncRunOptions = undefined>(
         rules: Rule<ConsequencePayload, RF, C, F, Ignore, CustomEngineRuleFuncRunOptions>[],
         validationContext: ValidationContext<C, Ignore>,
  functionsTable: F, ruleFunctionsTable: RF, runOptions: CustomEngineRuleFuncRunOptions)
diff --git a/src/lib/evaluator.ts b/src/lib/evaluator.ts
index 0da75fb..51c88a6 100644
--- a/src/lib/evaluator.ts
+++ b/src/lib/evaluator.ts
@@ -220,7 +220,7 @@ async function run<C extends Context, F extends FunctionsTable<C, CustomEvaluato
 }
 
 export const evaluate = async <C extends Context, F extends FunctionsTable<C, CustomEvaluatorFuncRunOptions>,
-    Ignore = never, CustomEvaluatorFuncRunOptions = {}>(
+    Ignore = never, CustomEvaluatorFuncRunOptions = undefined>(
         expression: Expression<C, F, Ignore, CustomEvaluatorFuncRunOptions>, context: C, functionsTable: F
         , runOptions: CustomEvaluatorFuncRunOptions)
     : Promise<boolean> => {
@@ -230,7 +230,7 @@ export const evaluate = async <C extends Context, F extends FunctionsTable<C, Cu
 
 // Throws in case of validation error. Does not run functions or compare fields
 export const validate = async <C extends Context, F extends FunctionsTable<C, CustomEvaluatorFuncRunOptions>,
-    Ignore = never, CustomEvaluatorFuncRunOptions = {}>(
+    Ignore = never, CustomEvaluatorFuncRunOptions = undefined>(
         expression: Expression<C, F, Ignore, CustomEvaluatorFuncRunOptions>,
         validationContext: ValidationContext<C, Ignore>, functionsTable: F, runOptions: CustomEvaluatorFuncRunOptions)
     : Promise<void> => {
diff --git a/src/lib/expressionHandler.ts b/src/lib/expressionHandler.ts
index 6725c18..8d439e3 100644
--- a/src/lib/expressionHandler.ts
+++ b/src/lib/expressionHandler.ts
@@ -7,7 +7,7 @@ import {
 } from '../types';
 
 export class ExpressionHandler<C extends Context, F extends FunctionsTable<C, CustomEvaluatorFuncRunOptions>,
-    Ignore = never, CustomEvaluatorFuncRunOptions = {}> {
+    Ignore = never, CustomEvaluatorFuncRunOptions = undefined> {
 
     constructor(private readonly expression: Expression<C, F, Ignore, CustomEvaluatorFuncRunOptions>,
                 private readonly functionsTable: F) {
diff --git a/src/lib/rulesEngine.ts b/src/lib/rulesEngine.ts
index 709a82b..4e3e5fd 100644
--- a/src/lib/rulesEngine.ts
+++ b/src/lib/rulesEngine.ts
@@ -8,7 +8,7 @@ import {evaluateRules, validateRules} from './engine';
 export class RulesEngine<ConsequencePayload, C extends Context,
     RF extends RuleFunctionsTable<C, ConsequencePayload, CustomEngineRuleFuncRunOptions>,
     F extends FunctionsTable<C, CustomEngineRuleFuncRunOptions>,
-    Ignore = never, CustomEngineRuleFuncRunOptions = {}> {
+    Ignore = never, CustomEngineRuleFuncRunOptions = undefined> {
 
     constructor(private readonly functionsTable: F, private readonly ruleFunctionsTable: RF) {
     }
diff --git a/src/types/engine.ts b/src/types/engine.ts
index 282d5d7..00391b7 100644
--- a/src/types/engine.ts
+++ b/src/types/engine.ts
@@ -30,7 +30,7 @@ export interface RuleDefinition<ConsequencePayload, C extends Context,
   consequence: RuleConsequence<ConsequencePayload, C, Ignore>;
 }
 
-export type EngineRuleFuncRunOptions<CustomEngineRuleFuncRunOptions> = {
+export type EngineRuleFuncRunOptions<CustomEngineRuleFuncRunOptions = undefined> = {
   custom: CustomEngineRuleFuncRunOptions;
   validation: boolean;
 }
@@ -54,6 +54,6 @@ export type RuleFunctionsParams<ConsequencePayload, C extends Context,
 
 export type Rule<ConsequencePayload, RF extends RuleFunctionsTable<C, ConsequencePayload,
     CustomEngineRuleFuncRunOptions>, C extends Context, F extends FunctionsTable<C, CustomEngineRuleFuncRunOptions>,
-    Ignore, CustomEngineRuleFuncRunOptions> =
+    Ignore = never, CustomEngineRuleFuncRunOptions = undefined> =
     RuleDefinition<ConsequencePayload, C, F, Ignore, CustomEngineRuleFuncRunOptions> |
     RequireOnlyOne<RuleFunctionsParams<ConsequencePayload, C, RF, CustomEngineRuleFuncRunOptions>>;
diff --git a/src/types/evaluator.ts b/src/types/evaluator.ts
index bb1b9ad..1301214 100644
--- a/src/types/evaluator.ts
+++ b/src/types/evaluator.ts
@@ -135,7 +135,7 @@ export type Expression<C extends Context, F extends FunctionsTable<C, CustomEval
     Ignore, CustomEvaluatorFuncRunOptions> =
     RequireOnlyOne<FullExpression<C, F, Ignore, CustomEvaluatorFuncRunOptions>>;
 
-export type EvaluatorFuncRunOptions<CustomEvaluatorFuncRunOptions> = {
+export type EvaluatorFuncRunOptions<CustomEvaluatorFuncRunOptions = undefined> = {
     custom: CustomEvaluatorFuncRunOptions;
     validation: boolean;
 }