diff --git a/app/controllers/admin/users_controller.rb b/app/controllers/admin/users_controller.rb
index 6c1e1de5ca7..b097ed82573 100644
--- a/app/controllers/admin/users_controller.rb
+++ b/app/controllers/admin/users_controller.rb
@@ -72,7 +72,8 @@ class Admin::UsersController < Admin::AdminController
 
   def trust_level
     guardian.ensure_can_change_trust_level!(@user)
-    BoostTrustLevel.new(@user, params[:level]).save!
+    logger = AdminLogger.new(current_user)
+    BoostTrustLevel.new(user: @user, level: params[:level], logger: logger).save!
     render_serialized(@user, AdminUserSerializer)
   end
 
diff --git a/app/models/admin_log.rb b/app/models/admin_log.rb
index 71dd383a12a..405bac7f79e 100644
--- a/app/models/admin_log.rb
+++ b/app/models/admin_log.rb
@@ -9,7 +9,7 @@ class AdminLog < ActiveRecord::Base
   validates_presence_of :action
 
   def self.actions
-    @actions ||= Enum.new(:delete_user)
+    @actions ||= Enum.new(:delete_user, :change_trust_level)
   end
 end
 
diff --git a/lib/admin_logger.rb b/lib/admin_logger.rb
index 53684172846..4adbf90d56d 100644
--- a/lib/admin_logger.rb
+++ b/lib/admin_logger.rb
@@ -13,4 +13,14 @@ class AdminLogger
       details: [:id, :username, :name, :created_at, :trust_level, :last_seen_at, :last_emailed_at].map { |x| "#{x}: #{deleted_user.send(x)}" }.join(', ')
     )
   end
-end
\ No newline at end of file
+
+  def log_trust_level_change(user, new_trust_level)
+    raise Discourse::InvalidParameters.new('user is nil') unless user and user.is_a?(User)
+    raise Discourse::InvalidParameters.new('new trust level is invalid') unless TrustLevel.levels.values.include? new_trust_level
+    AdminLog.create!(
+      action: AdminLog.actions[:change_trust_level],
+      admin_id: @admin.id,
+      details: [:id, :username, :name, :created_at, :trust_level, :last_seen_at, :last_emailed_at].map { |x| "#{x}: #{user.send(x)}" }.join(', ') + "new trust level: #{new_trust_level}"
+    )
+  end
+end
diff --git a/lib/boost_trust_level.rb b/lib/boost_trust_level.rb
index 597f380866e..50785270ea0 100644
--- a/lib/boost_trust_level.rb
+++ b/lib/boost_trust_level.rb
@@ -2,19 +2,22 @@ require_dependency 'promotion'
 
 class BoostTrustLevel
 
-  def initialize(user, level)
-    @user = user
-    @level = level.to_i
+  def initialize(args)
+    @user = args[:user]
+    @level = args[:level].to_i
     @promotion = Promotion.new(@user)
     @trust_levels = TrustLevel.levels
+    @logger = args[:logger]
   end
 
   def save!
-    if @level < @user.trust_level
-      demote!
-    else
-      @user.update_attributes!(trust_level: @level)
-    end
+    success = if @level < @user.trust_level
+                demote!
+              else
+                @user.update_attributes!(trust_level: @level)
+              end
+    @logger.log_trust_level_change(@user, @level)
+    success
   end
 
   protected
diff --git a/spec/components/admin_logger_spec.rb b/spec/components/admin_logger_spec.rb
index 5162cf9bc23..f98517e6b5e 100644
--- a/spec/components/admin_logger_spec.rb
+++ b/spec/components/admin_logger_spec.rb
@@ -32,4 +32,30 @@ describe AdminLogger do
     end
   end
 
+  describe 'log_trust_level_change' do
+    let(:admin) { Fabricate(:admin) }
+    let(:user) { Fabricate(:user) }
+    let(:new_trust_level) { TrustLevel.levels[:basic] }
+
+    subject(:log_trust_level_change) { AdminLogger.new(admin).log_trust_level_change(user, new_trust_level) }
+
+    it 'raises an error when user or trust level is nil' do
+      expect { AdminLogger.new(admin).log_trust_level_change(nil, new_trust_level) }.to raise_error(Discourse::InvalidParameters)
+      expect { AdminLogger.new(admin).log_trust_level_change(user, nil) }.to raise_error(Discourse::InvalidParameters)
+    end
+
+    it 'raises an error when user is not a User' do
+      expect { AdminLogger.new(admin).log_trust_level_change(1, new_trust_level) }.to raise_error(Discourse::InvalidParameters)
+    end
+
+    it 'raises an error when new trust level is not a Trust Level' do
+      max_level = TrustLevel.levels.values.max
+      expect { AdminLogger.new(admin).log_trust_level_change(user, max_level + 1) }.to raise_error(Discourse::InvalidParameters)
+    end
+
+    it 'creates a new AdminLog record' do
+      expect { log_trust_level_change }.to change { AdminLog.count }.by(1)
+      AdminLog.last.details.should include "new trust level: #{new_trust_level}"
+    end
+  end
 end
diff --git a/spec/components/boost_trust_level_spec.rb b/spec/components/boost_trust_level_spec.rb
index 26412079337..3974aecbb62 100644
--- a/spec/components/boost_trust_level_spec.rb
+++ b/spec/components/boost_trust_level_spec.rb
@@ -1,16 +1,25 @@
 require 'spec_helper'
 require 'boost_trust_level'
+require 'admin_logger'
 
 describe BoostTrustLevel do
 
   let(:user) { Fabricate(:user) }
+  let(:logger) { AdminLogger.new(Fabricate(:admin)) }
+
 
   it "should upgrade the trust level of a user" do
-    boostr = BoostTrustLevel.new(user, TrustLevel.levels[:basic])
+    boostr = BoostTrustLevel.new(user: user, level: TrustLevel.levels[:basic], logger: logger)
     boostr.save!.should be_true
     user.trust_level.should == TrustLevel.levels[:basic]
   end
 
+  it "should log the action" do
+    AdminLogger.any_instance.expects(:log_trust_level_change).with(user, TrustLevel.levels[:basic]).once
+    boostr = BoostTrustLevel.new(user: user, level: TrustLevel.levels[:basic], logger: logger)
+    boostr.save!
+  end
+
   describe "demotions" do
     before { user.update_attributes(trust_level: TrustLevel.levels[:newuser]) }
 
@@ -21,8 +30,9 @@ describe BoostTrustLevel do
         user.update_attributes(trust_level: TrustLevel.levels[:basic])
       end
 
-      it "should demote the user" do
-        boostr = BoostTrustLevel.new(user, TrustLevel.levels[:newuser])
+      it "should demote the user and log the action" do
+        AdminLogger.any_instance.expects(:log_trust_level_change).with(user, TrustLevel.levels[:newuser]).once
+        boostr = BoostTrustLevel.new(user: user, level: TrustLevel.levels[:newuser], logger: logger)
         boostr.save!.should be_true
         user.trust_level.should == TrustLevel.levels[:newuser]
       end
@@ -38,11 +48,13 @@ describe BoostTrustLevel do
         user.update_attributes(trust_level: TrustLevel.levels[:basic])
       end
 
-      it "should not demote the user" do
-        boostr = BoostTrustLevel.new(user, TrustLevel.levels[:newuser])
+      it "should not demote the user and not log the action" do
+        AdminLogger.any_instance.expects(:log_trust_level_change).with(user, TrustLevel.levels[:newuser]).never
+        boostr = BoostTrustLevel.new(user: user, level: TrustLevel.levels[:newuser], logger: logger)
         expect { boostr.save! }.to raise_error(Discourse::InvalidAccess, "You attempted to demote #{user.name} to 'newuser'. However their trust level is already 'basic'. #{user.name} will remain at 'basic'")
         user.trust_level.should == TrustLevel.levels[:basic]
       end
+
     end
   end
 end
diff --git a/spec/controllers/admin/users_controller_spec.rb b/spec/controllers/admin/users_controller_spec.rb
index 35fbaab5887..036e557bb0a 100644
--- a/spec/controllers/admin/users_controller_spec.rb
+++ b/spec/controllers/admin/users_controller_spec.rb
@@ -137,12 +137,14 @@ describe Admin::UsersController do
       end
 
       it "upgrades the user's trust level" do
+        AdminLogger.any_instance.expects(:log_trust_level_change).with(@another_user, 2).once
         xhr :put, :trust_level, user_id: @another_user.id, level: 2
         @another_user.reload
         @another_user.trust_level.should == 2
       end
 
       it "raises an error when demoting a user below their current trust level" do
+        AdminLogger.any_instance.expects(:log_trust_level_change).with(@another_user, TrustLevel.levels[:newuser]).never
         @another_user.topics_entered = SiteSetting.basic_requires_topics_entered + 1
         @another_user.posts_read_count = SiteSetting.basic_requires_read_posts + 1
         @another_user.time_read = SiteSetting.basic_requires_time_spent_mins * 60