diff --git a/README.md b/README.md
index 7aeb37d5..526eb7eb 100755
--- a/README.md
+++ b/README.md
@@ -29,7 +29,7 @@ You will then have a development server running on `localhost:3300`.
 
 ### Ship and Module Database
 
-See the [Data wiki](https://github.com/cmmcleod/coriolis-data/wiki) for details on structure, etc.
+See the [Data wiki](https://github.com/EDCD/coriolis-data/wiki) for details on structure, etc.
 
 ## Deployment
 
diff --git a/src/app/components/AvailableModulesMenu.jsx b/src/app/components/AvailableModulesMenu.jsx
index 593b6df8..2919affb 100644
--- a/src/app/components/AvailableModulesMenu.jsx
+++ b/src/app/components/AvailableModulesMenu.jsx
@@ -287,6 +287,8 @@ export default class AvailableModulesMenu extends TranslatedComponent {
       // the maximum does not apply
       } else if (m.experimental && (!mountedModule || !mountedModule.experimental)) {
         disabled = 4 <= ship.hardpoints.filter(o => o.m && o.m.experimental).length;
+      } else if (m.grp === 'mlc' && (!mountedModule || mountedModule.grp !== 'mlc')) {
+        disabled = 1 <= ship.internal.filter(o => o.m && o.m.grp === 'mlc').length;
       }
       let active = mountedModule && mountedModule.id === m.id;
       let classes = cn(m.name ? 'lc' : 'c', {