diff --git a/src/main/java/net/hostsharing/hsadminng/hs/office/contact/HsOfficeContactRbacRepository.java b/src/main/java/net/hostsharing/hsadminng/hs/office/contact/HsOfficeContactRbacRepository.java
index ec2b15d1..1e82a7ac 100644
--- a/src/main/java/net/hostsharing/hsadminng/hs/office/contact/HsOfficeContactRbacRepository.java
+++ b/src/main/java/net/hostsharing/hsadminng/hs/office/contact/HsOfficeContactRbacRepository.java
@@ -36,9 +36,9 @@ public interface HsOfficeContactRbacRepository extends Repository<HsOfficeContac
 
     static String emailRegEx(@NotNull String emailAddress) {
         // TODO.impl: find more secure solution, maybe we substitute a placeholder with the whole expression?
-        if (emailAddress.contains("'") || emailAddress.endsWith("\\") ) {
+        if (emailAddress.contains("'") || emailAddress.contains("\"") || emailAddress.endsWith("\\") ) {
             throw new ValidationException(
-                    "emailAddress contains invalid characters: " + emailAddress);
+                    "emailAddressRegEx contains invalid characters: " + emailAddress);
         }
         return emailAddress.replace("%", ".*"); // the JSON-matcher in PostgreSQL needs a wildcard
     }