diff --git a/app/javascript/mastodon/actions/compose.js b/app/javascript/mastodon/actions/compose.js
index 2d58a71fe..da7bd3cb0 100644
--- a/app/javascript/mastodon/actions/compose.js
+++ b/app/javascript/mastodon/actions/compose.js
@@ -60,6 +60,7 @@ export const COMPOSE_POLL_SETTINGS_CHANGE = 'COMPOSE_POLL_SETTINGS_CHANGE';
 
 const messages = defineMessages({
   uploadErrorLimit: { id: 'upload_error.limit', defaultMessage: 'File upload limit exceeded.' },
+  uploadErrorPoll:  { id: 'upload_error.poll', defaultMessage: 'File upload not allowed with polls.' },
 });
 
 export function changeCompose(text) {
@@ -207,6 +208,12 @@ export function uploadCompose(files) {
       dispatch(showAlert(undefined, messages.uploadErrorLimit));
       return;
     }
+
+    if (getState().getIn(['compose', 'poll'])) {
+      dispatch(showAlert(undefined, messages.uploadErrorPoll));
+      return;
+    }
+
     dispatch(uploadComposeRequest());
 
     for (const [i, f] of Array.from(files).entries()) {
diff --git a/app/javascript/mastodon/components/icon_button.js b/app/javascript/mastodon/components/icon_button.js
index fbb42f78f..9d8a8d06b 100644
--- a/app/javascript/mastodon/components/icon_button.js
+++ b/app/javascript/mastodon/components/icon_button.js
@@ -86,6 +86,7 @@ export default class IconButton extends React.PureComponent {
           onClick={this.handleClick}
           style={style}
           tabIndex={tabIndex}
+          disabled={disabled}
         >
           <Icon id={icon} fixedWidth aria-hidden='true' />
         </button>
@@ -104,6 +105,7 @@ export default class IconButton extends React.PureComponent {
             onClick={this.handleClick}
             style={style}
             tabIndex={tabIndex}
+            disabled={disabled}
           >
             <Icon id={icon} style={{ transform: `rotate(${rotate}deg)` }} fixedWidth aria-hidden='true' />
           </button>
diff --git a/app/models/poll.rb b/app/models/poll.rb
index ab7236d45..da2e25e71 100644
--- a/app/models/poll.rb
+++ b/app/models/poll.rb
@@ -15,6 +15,7 @@
 #  last_fetched_at :datetime
 #  created_at      :datetime         not null
 #  updated_at      :datetime         not null
+#  lock_version    :integer          default(0), not null
 #
 
 class Poll < ApplicationRecord
diff --git a/app/models/poll_vote.rb b/app/models/poll_vote.rb
index 9ad66bbf8..ad24eb691 100644
--- a/app/models/poll_vote.rb
+++ b/app/models/poll_vote.rb
@@ -32,5 +32,8 @@ class PollVote < ApplicationRecord
   def increment_counter_cache
     poll.cached_tallies[choice] = (poll.cached_tallies[choice] || 0) + 1
     poll.save
+  rescue ActiveRecord::StaleObjectError
+    poll.reload
+    retry
   end
 end
diff --git a/db/migrate/20190306145741_add_lock_version_to_polls.rb b/db/migrate/20190306145741_add_lock_version_to_polls.rb
new file mode 100644
index 000000000..cf506404d
--- /dev/null
+++ b/db/migrate/20190306145741_add_lock_version_to_polls.rb
@@ -0,0 +1,6 @@
+class AddLockVersionToPolls < ActiveRecord::Migration[5.2]
+  def change
+    add_column :polls, :lock_version, :integer, null: false, default: 0
+  end
+end
+
diff --git a/db/schema.rb b/db/schema.rb
index 48c00511b..858cd1e9b 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2019_03_04_152020) do
+ActiveRecord::Schema.define(version: 2019_03_06_145741) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -475,6 +475,7 @@ ActiveRecord::Schema.define(version: 2019_03_04_152020) do
     t.datetime "last_fetched_at"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
+    t.integer "lock_version", default: 0, null: false
     t.index ["account_id"], name: "index_polls_on_account_id"
     t.index ["status_id"], name: "index_polls_on_status_id"
   end