diff --git a/cucumber-expressions/javascript/src/ParameterTypeRegistry.ts b/cucumber-expressions/javascript/src/ParameterTypeRegistry.ts
index 029df6072a..1cc4f8e5db 100644
--- a/cucumber-expressions/javascript/src/ParameterTypeRegistry.ts
+++ b/cucumber-expressions/javascript/src/ParameterTypeRegistry.ts
@@ -49,7 +49,7 @@ export default class ParameterTypeRegistry {
         'string',
         ParameterTypeRegistry.STRING_REGEXP,
         String,
-        s => s.replace(/\\"/g, '"').replace(/\\'/g, "'"),
+        s => (s || '').replace(/\\"/g, '"').replace(/\\'/g, "'"),
         true,
         false
       )