diff --git a/code/Model/Recipient/EmailRecipient.php b/code/Model/Recipient/EmailRecipient.php
index e8e37e1..6a056d8 100644
--- a/code/Model/Recipient/EmailRecipient.php
+++ b/code/Model/Recipient/EmailRecipient.php
@@ -542,7 +542,7 @@ class EmailRecipient extends DataObject
             $templatePath = substr($absoluteFilename, strlen($prefixToStrip) + 1);
 
             // Optionally remove "templates/" ("templates\" on Windows respectively) prefixes
-            if (preg_match('#(?<=templates' . DIRECTORY_SEPARATOR . ').*$#', $templatePath, $matches)) {
+            if (preg_match('#(?<=templates' . preg_quote(DIRECTORY_SEPARATOR, '#') . ').*$#', $templatePath, $matches)) {
                 $templatePath = $matches[0];
             }