diff --git a/app/views/shipit/_variables.html.erb b/app/views/shipit/_variables.html.erb
index c87397154..a43dd6c93 100644
--- a/app/views/shipit/_variables.html.erb
+++ b/app/views/shipit/_variables.html.erb
@@ -9,7 +9,7 @@
           <% if variable.select %>
             <%= field.select variable.name, options_for_select([["Please select...", { disabled: "disabled" }]] + variable.select, variable.default || "Please select...") %>
           <% else %>
-            <%= field.text_field variable.name, value: variable.default %>
+            <%= field.text_field variable.name, value: params[variable.name].presence || variable.default %>
           <% end %>
           <%= field.label variable.name, variable.title || variable.name %>
         </p>
diff --git a/test/controllers/tasks_controller_test.rb b/test/controllers/tasks_controller_test.rb
index adbd9355c..ff5fc08c2 100644
--- a/test/controllers/tasks_controller_test.rb
+++ b/test/controllers/tasks_controller_test.rb
@@ -11,9 +11,16 @@ class TasksControllerTest < ActionController::TestCase
       session[:user_id] = shipit_users(:walrus).id
     end
 
-    test "tasks defined in the shipit.yml can be displayed" do
+    test "tasks defined in the shipit.yml can be displayed with default variable values" do
       get :new, params: { stack_id: @stack, definition_id: @definition.id }
       assert_response :ok
+      assert_select 'input[name="task[env][FOO]"][value="1"]'
+    end
+
+    test "it is possible to provide a default value override for a task" do
+      get :new, params: { stack_id: @stack, definition_id: @definition.id, FOO: '42' }
+      assert_response :ok
+      assert_select 'input[name="task[env][FOO]"][value="42"]'
     end
 
     test "tasks defined in the shipit.yml can't be triggered if the stack is being deployed" do