diff --git a/app/models/discourse_single_sign_on.rb b/app/models/discourse_single_sign_on.rb
index 52eff1357..b75ebd461 100644
--- a/app/models/discourse_single_sign_on.rb
+++ b/app/models/discourse_single_sign_on.rb
@@ -92,7 +92,7 @@ class DiscourseSingleSignOn < SingleSignOn
         sso_record.last_payload = unsigned_payload
         sso_record.external_id = external_id
       else
-        sso_record = user.create_single_sign_on_record(last_payload: unsigned_payload,
+        user.create_single_sign_on_record(last_payload: unsigned_payload,
                                           external_id: external_id,
                                           external_username: username,
                                           external_email: email,
diff --git a/app/models/invite_redeemer.rb b/app/models/invite_redeemer.rb
index bda7870aa..15c2cb6cc 100644
--- a/app/models/invite_redeemer.rb
+++ b/app/models/invite_redeemer.rb
@@ -99,7 +99,7 @@ InviteRedeemer = Struct.new(:invite, :username, :name) do
   end
 
   def approve_account_if_needed
-    invited_user.approve(invite.invited_by_id, send_email=false)
+    invited_user.approve(invite.invited_by_id, false)
   end
 
   def notify_invitee
diff --git a/app/models/plugin_store.rb b/app/models/plugin_store.rb
index 5ef649e07..ecf8d9c73 100644
--- a/app/models/plugin_store.rb
+++ b/app/models/plugin_store.rb
@@ -8,7 +8,7 @@ class PluginStore
 
   def self.set(plugin_name, key, value)
     hash = {plugin_name: plugin_name, key: key}
-    row = PluginStoreRow.find_by(hash) || row = PluginStoreRow.new(hash)
+    row = PluginStoreRow.find_by(hash) || PluginStoreRow.new(hash)
 
     row.type_name = determine_type(value)
     # nil are stored as nil
diff --git a/app/models/topic_embed.rb b/app/models/topic_embed.rb
index ffb1f6915..1d284d80a 100644
--- a/app/models/topic_embed.rb
+++ b/app/models/topic_embed.rb
@@ -151,7 +151,7 @@ class TopicEmbed < ActiveRecord::Base
   def self.expanded_for(post)
     Rails.cache.fetch("embed-topic:#{post.topic_id}", expires_in: 10.minutes) do
       url = TopicEmbed.where(topic_id: post.topic_id).pluck(:embed_url).first
-      title, body = TopicEmbed.find_remote(url)
+      _title, body = TopicEmbed.find_remote(url)
       body << TopicEmbed.imported_from_html(url)
       body
     end
diff --git a/app/models/user.rb b/app/models/user.rb
index b9ebf9034..1ec99c667 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -173,7 +173,6 @@ class User < ActiveRecord::Base
   end
 
   def change_username(new_username)
-    current_username = self.username
     self.username = new_username
     save
   end
diff --git a/lib/cooked_post_processor.rb b/lib/cooked_post_processor.rb
index f8bed1bc3..208aa5d3a 100644
--- a/lib/cooked_post_processor.rb
+++ b/lib/cooked_post_processor.rb
@@ -69,7 +69,7 @@ class CookedPostProcessor
     @doc.css("img[src^='data']") -
     # minus, image inside oneboxes
     oneboxed_images -
-    # minux, images inside quotes
+    # minus, images inside quotes
     @doc.css(".quote img")
   end