diff --git a/lib/machines.js b/lib/machines.js
index 829a786f..e373c31f 100644
--- a/lib/machines.js
+++ b/lib/machines.js
@@ -484,6 +484,7 @@ function getProject (projectId, create) {
         update: '',
         logs: ''
       },
+      traits: ['c9sdk'],
       data: {}
     };
     projects[projectId] = project;
diff --git a/lib/users.js b/lib/users.js
index 92972574..e58b7b69 100644
--- a/lib/users.js
+++ b/lib/users.js
@@ -288,6 +288,18 @@ function getOrCreateUser (email) {
       if (!machine.project) {
         machine.project = projectId;
       }
+
+      // Temporary migration code: Previous machines didn't have traits.
+      if (!machine.traits) {
+        const updated = new Date(machine.data.updated);
+        const c9sdkStart = new Date('2017-08-02');
+
+        machine.traits = [];
+
+        if (updated > c9sdkStart) {
+          machine.traits.push('c9sdk');
+        }
+      }
     }
   }
 
diff --git a/templates/contributions.html b/templates/contributions.html
index 4c1a08d0..f99f64e8 100644
--- a/templates/contributions.html
+++ b/templates/contributions.html
@@ -29,9 +29,8 @@ <h4>{{= name in html}}</h4>
               </a>
               <ul class="dropdown-menu">{{
                 const updated = new Date(machine.data.updated);
-                const c9sdkStart = new Date('2017-08-02');
                 const c9ioEnd = new Date('2017-09-02');
-                if (updated > c9sdkStart && updated < c9ioEnd) { }}
+                if (machine.traits.includes('c9sdk') && updated < c9ioEnd) { }}
                 <li>
                   <a href="https://c9.io/open/ssh?name={{= projectId in id}}-{{= id in id}}&description={{= project.name in uri}}%20on%20janitor.technology&host={{= machine.docker.host in uri}}&port={{= machine.docker.ports['22'].port in integer}}&user=user&workspaceDir={{= project.docker.path in uri}}&nodePath=%2Fhome%2Fuser%2F.c9%2Fnode%2Fbin%2Fnode" target="_blank">Edit via c9.io</a>
                 </li>{{ } }}
@@ -41,8 +40,8 @@ <h4>{{= name in html}}</h4>
               </ul>
               <a class="btn btn-default" href="https://{{= machine.docker.host in uri}}/{{= machine.docker.container.slice(0,16) in uri}}/8088/vnc.html" target="_blank">VNC</a>
               <a class="btn btn-primary"{{
-                if (updated < c9sdkStart) { }} href="https://c9.io/open/ssh?name={{= projectId in id}}-{{= id in id}}&description={{= project.name in uri}}%20on%20janitor.technology&host={{= machine.docker.host in uri}}&port={{= machine.docker.ports['22'].port in integer}}&user=user&workspaceDir={{= project.docker.path in uri}}&nodePath=%2Fhome%2Fuser%2F.c9%2Fnode%2Fbin%2Fnode" {{ }
-                else { }} href="https://{{= machine.docker.host in uri}}/{{= machine.docker.container.slice(0,16) in uri}}/8089/ide.html" {{ }
+                if (machine.traits.includes('c9sdk')) { }} href="https://{{= machine.docker.host in uri}}/{{= machine.docker.container.slice(0,16) in uri}}/8089/ide.html" {{ }
+                else { }} href="https://c9.io/open/ssh?name={{= projectId in id}}-{{= id in id}}&description={{= project.name in uri}}%20on%20janitor.technology&host={{= machine.docker.host in uri}}&port={{= machine.docker.ports['22'].port in integer}}&user=user&workspaceDir={{= project.docker.path in uri}}&nodePath=%2Fhome%2Fuser%2F.c9%2Fnode%2Fbin%2Fnode" {{ }
               }}target="_blank"><span class="hidden-xs">Edit in </span>Cloud9</a>
             </div>
           </div>