diff --git a/source/java/org/alfresco/repo/usage/UsageQuotaProtector.java b/source/java/org/alfresco/repo/usage/UsageQuotaProtector.java
index 17a388ccd3..47548f8c51 100644
--- a/source/java/org/alfresco/repo/usage/UsageQuotaProtector.java
+++ b/source/java/org/alfresco/repo/usage/UsageQuotaProtector.java
@@ -110,7 +110,7 @@ public class UsageQuotaProtector implements NodeServicePolicies.OnUpdateProperti
         }
         
         // Check for change in sizeQuota
-        if ((sizeQuotaBefore != sizeQuotaAfter) && (! authorityService.hasAdminAuthority()))
+        if ((sizeQuotaBefore != sizeQuotaAfter) && (! (authorityService.hasAdminAuthority() || authenticationService.isCurrentUserTheSystemUser())))
         {
             throw new AlfrescoRuntimeException("Update failed: protected property 'sizeQuota'");
         }