diff --git a/Classes/Template.php b/Classes/Template.php
index e40d2e1..7f08209 100644
--- a/Classes/Template.php
+++ b/Classes/Template.php
@@ -201,7 +201,8 @@ public function isApplicable(array $context)
     protected function setProperties(NodeInterface $node, array $context)
     {
         foreach ($this->properties as $propertyName => $propertyValue) {
-            if (preg_match(\Neos\Eel\Package::EelExpressionRecognizer, $propertyValue)) {
+            //evaluate Eel only on string properties
+            if (is_string($propertyValue) && preg_match(\Neos\Eel\Package::EelExpressionRecognizer, $propertyValue)) {
                 $this->persistenceManager->persistAll();
                 $propertyValue = $this->eelEvaluationService->evaluateEelExpression($propertyValue, $context);
             }