diff --git a/packages/form-js-viewer/src/core/Validator.js b/packages/form-js-viewer/src/core/Validator.js
index 4df86206d..a79f9072b 100644
--- a/packages/form-js-viewer/src/core/Validator.js
+++ b/packages/form-js-viewer/src/core/Validator.js
@@ -76,6 +76,15 @@ export class Validator {
 
     errors = runPresetValidation(field, evaluatedValidation, value, errors);
 
+    if ('custom' in evaluatedValidation && value && evaluatedValidation.custom.length) {
+      const { custom } = evaluatedValidation;
+      custom.forEach(({ condition, message }) => {
+        if (condition && !runExpressionEvaluation(this._expressionLanguage, value, expressionContextInfo)) {
+          errors = [...errors, message];
+        }
+      });
+    }
+
     return errors;
   }
 }
@@ -199,7 +208,7 @@ function oldEvaluateFEELValues(validate, expressionLanguage, conditionChecker, f
 
     // replace validate property with evaluated value
     if (evaluatedValue) {
-      set(evaluatedValidate, path, evaluatedValue);
+      set(validate, propertyPath.split('.'), evaluatedValue);
     }
   });