diff --git a/src/Orchard.Web/Modules/Orchard.MultiTenancy/Commands/TenantCommand.cs b/src/Orchard.Web/Modules/Orchard.MultiTenancy/Commands/TenantCommand.cs
index 890236e7d..78b6046d6 100644
--- a/src/Orchard.Web/Modules/Orchard.MultiTenancy/Commands/TenantCommand.cs
+++ b/src/Orchard.Web/Modules/Orchard.MultiTenancy/Commands/TenantCommand.cs
@@ -112,8 +112,8 @@ namespace Orchard.MultiTenancy.Commands {
                     DataTablePrefix = DataTablePrefix,
                     RequestUrlHost = UrlHost,
                     RequestUrlPrefix = UrlPrefix,
-                    Themes = Themes.Split(';'),
-                    Modules = Modules.Split(';')
+                    Themes = Themes != null ? Themes.Split(';') : new string[] { },
+                    Modules = Modules != null ? Modules.Split(';') : new string[] { }
                 });
         }