diff --git a/rater/rater.xsd b/rater/rater.xsd
index d91c6584..7cbc871b 100644
--- a/rater/rater.xsd
+++ b/rater/rater.xsd
@@ -150,7 +150,7 @@
     </xs:annotation>
 
     <xs:restriction base="xs:string">
-      <xs:pattern value="_[a-zA-Z0-9@\{\}-]+_|@[a-z][a-zA-Z0-9]*@" />
+      <xs:pattern value="_+[a-zA-Z0-9@\{\}-]+_+|@[a-z][a-zA-Z0-9]*@" />
     </xs:restriction>
   </xs:simpleType>
 
diff --git a/src/current/rater.xsd b/src/current/rater.xsd
index 650fa87a..a9f08136 100644
--- a/src/current/rater.xsd
+++ b/src/current/rater.xsd
@@ -148,7 +148,7 @@
     </xs:annotation>
 
     <xs:restriction base="xs:string">
-      <xs:pattern value="_[a-zA-Z0-9@\{\}-]+_|@[a-z][a-zA-Z0-9]*@" />
+      <xs:pattern value="_+[a-zA-Z0-9@\{\}-]+_+|@[a-z][a-zA-Z0-9]*@" />
     </xs:restriction>
   </xs:simpleType>