diff --git a/src/lib/utils/options/options.ts b/src/lib/utils/options/options.ts
index 5b679fa13..ef7fbd3e7 100644
--- a/src/lib/utils/options/options.ts
+++ b/src/lib/utils/options/options.ts
@@ -1,7 +1,7 @@
 import * as _ from 'lodash';
 import * as ts from 'typescript';
 
-import { DeclarationOption, ParameterScope, convert, TypeDocOptions, KeyToDeclaration, TypeDocAndTSOptions, TypeDocOptionMap } from './declaration';
+import { DeclarationOption, ParameterScope, ParameterType, convert, TypeDocOptions, KeyToDeclaration, TypeDocAndTSOptions, TypeDocOptionMap } from './declaration';
 import { Logger } from '../loggers';
 import { Result, Ok, Err } from '../result';
 import { insertPrioritySorted } from '../array';
@@ -109,10 +109,7 @@ export class Options {
      */
     reset() {
         for (const declaration of this._declarations.values()) {
-            if (declaration.scope !== ParameterScope.TypeScript) {
-                this._values[declaration.name] = convert(declaration.defaultValue, declaration)
-                    .expect(`Failed to validate default value for ${declaration.name}`);
-            }
+            this.setOptionValueToDefault(declaration);
         }
         this._compilerOptions = {};
     }
@@ -169,10 +166,7 @@ export class Options {
             }
         }
 
-        if (declaration.scope !== ParameterScope.TypeScript) {
-            this._values[declaration.name] = convert(declaration.defaultValue, declaration)
-                .expect(`Failed to validate default value for ${declaration.name}`);
-        }
+        this.setOptionValueToDefault(declaration);
     }
 
     /**
@@ -320,6 +314,22 @@ export class Options {
         }
         return errors.length ? Err(errors) : Ok(void 0);
     }
+
+    /**
+     * Sets the value of a given option to its default value.
+     * @param declaration The option whoes value should be reset.
+     */
+    private setOptionValueToDefault(declaration: Readonly<DeclarationOption>): void {
+        if (declaration.scope !== ParameterScope.TypeScript) {
+            // No nead to convert the defaultValue for a map type as it has to be of a specific type
+            if (declaration.type === ParameterType.Map) {
+                this._values[declaration.name] = declaration.defaultValue;
+            } else {
+                this._values[declaration.name] = convert(declaration.defaultValue, declaration)
+                    .expect(`Failed to validate default value for ${declaration.name}`);
+            }
+        }
+    }
 }
 
 /**
diff --git a/src/test/utils/options/options.test.ts b/src/test/utils/options/options.test.ts
index 4ff963e4f..60b678281 100644
--- a/src/test/utils/options/options.test.ts
+++ b/src/test/utils/options/options.test.ts
@@ -25,6 +25,21 @@ describe('Options', () => {
         options.removeDeclarationByName(declaration.name);
     });
 
+    it('Does not error if a map declaration has a default value that is not part of the map of possible values', () => {
+        logger.resetErrors();
+        options.addDeclaration({
+            name: 'testMapDeclarationWithForeignDefaultValue',
+            help: '',
+            type: ParameterType.Map,
+            map: new Map([
+                ['a', 1],
+                ['b', 2]
+            ]),
+            defaultValue: 0
+        });
+        equal(logger.hasErrors(), false);
+    });
+
     it('Supports removing a declaration by name', () => {
         options.addDeclaration({ name: 'not-an-option', help: '' });
         options.removeDeclarationByName('not-an-option');