diff --git a/config/src/main/resources/org/springframework/security/config/spring-security-4.2.rnc b/config/src/main/resources/org/springframework/security/config/spring-security-4.2.rnc
index fb36fae3b6..aefbbbdefb 100644
--- a/config/src/main/resources/org/springframework/security/config/spring-security-4.2.rnc
+++ b/config/src/main/resources/org/springframework/security/config/spring-security-4.2.rnc
@@ -545,8 +545,8 @@ concurrency-control =
 	element concurrency-control {concurrency-control.attlist, empty}
 
 concurrency-control.attlist &=
-	## The maximum number of sessions a single authenticated user can have open at the same time. Defaults to "1".
-	attribute max-sessions {xsd:positiveInteger}?
+	## The maximum number of sessions a single authenticated user can have open at the same time. Defaults to "1". A negative value denotes unlimitted sessions.
+	attribute max-sessions {xsd:integer}?
 concurrency-control.attlist &=
 	## The URL a user will be redirected to if they attempt to use a session which has been "expired" because they have logged in again.
 	attribute expired-url {xsd:token}?
diff --git a/config/src/main/resources/org/springframework/security/config/spring-security-4.2.xsd b/config/src/main/resources/org/springframework/security/config/spring-security-4.2.xsd
index fdb8532d56..2e1f246fe0 100644
--- a/config/src/main/resources/org/springframework/security/config/spring-security-4.2.xsd
+++ b/config/src/main/resources/org/springframework/security/config/spring-security-4.2.xsd
@@ -1756,7 +1756,7 @@
       <xs:attribute name="max-sessions" type="xs:integer">
          <xs:annotation>
             <xs:documentation>The maximum number of sessions a single authenticated user can have open at the same time.
-                Defaults to "1".
+                Defaults to "1". A negative value denotes unlimitted sessions.
                 </xs:documentation>
          </xs:annotation>
       </xs:attribute>