diff --git a/plinth/setup.py b/plinth/setup.py
index 51c1ec2ce..5e9156f16 100644
--- a/plinth/setup.py
+++ b/plinth/setup.py
@@ -143,8 +143,6 @@ class Helper(object):
             return 'up-to-date'
 
         if not current_version:
-            if any(self.list_unavailable_packages()):
-                return 'unavailable'
             return 'needs-setup'
         else:
             return 'needs-update'
@@ -164,17 +162,16 @@ class Helper(object):
         """Set a module's setup version."""
         from . import models
 
-        models.Module.objects.update_or_create(pk=self.module_name, defaults={
-            'setup_version': version
-        })
+        models.Module.objects.update_or_create(
+            pk=self.module_name, defaults={'setup_version': version})
 
-    def list_unavailable_packages(self):
+    def has_unavailable_packages(self):
         """List the unavailable packages managed by the module (if any)."""
         cache = apt.Cache()
         managed_pkgs = getattr(self.module, 'managed_packages', [])
-        unavailable_pkgs = [pkg_name for pkg_name in managed_pkgs
-                            if pkg_name not in cache]
-        return unavailable_pkgs
+        unavailable_pkgs = (pkg_name for pkg_name in managed_pkgs
+                            if pkg_name not in cache)
+        return any(unavailable_pkgs)
 
 
 def init(module_name, module):
diff --git a/plinth/templates/setup.html b/plinth/templates/setup.html
index a5c7eeb03..9d79bce43 100644
--- a/plinth/templates/setup.html
+++ b/plinth/templates/setup.html
@@ -72,22 +72,22 @@
             Please wait for a few moments before trying again.
           {% endblocktrans %}
         </div>
-      {% elif setup_helper.get_state == 'unavailable' %}
+      {% elif setup_helper.has_unavailable_packages %}
         <div class="alert alert-warning" role="alert">
           {% blocktrans trimmed %}
-            This application is currently unavailable in your distribution.
-         {% endblocktrans %}
+            This application is currently not available in your distribution.
+          {% endblocktrans %}
         </div>
       {% endif %}
 
       <input type="submit" class="btn btn-md btn-primary"
-             {{ package_manager_is_busy|yesno:'disabled="disabled"' }}
+             {% if package_manager_is_busy or setup_helper.has_unavailable_packages %}
+             disabled="disabled"
+             {% endif %}
              {% if setup_helper.get_state == 'needs-setup' %}
              value="{% trans "Install" %}"
              {% elif setup_helper.get_state == 'needs-upgrade' %}
              value="{% trans "Update" %}"
-             {% elif setup_helper.get_state == 'unavailable' %}
-             value="{% trans "Install" %}" disabled="disabled"
              {% endif %} />
 
     </form>