diff --git a/app/assets/javascripts/discourse/components/flag-action-type.js.es6 b/app/assets/javascripts/discourse/components/flag-action-type.js.es6
index 7f0ffb70edc..fe2b5c601a0 100644
--- a/app/assets/javascripts/discourse/components/flag-action-type.js.es6
+++ b/app/assets/javascripts/discourse/components/flag-action-type.js.es6
@@ -34,13 +34,13 @@ export default Ember.Component.extend({
 
   @computed('message.length')
   customMessageLengthClasses(messageLength) {
-    return (messageLength < Discourse.SiteSettings.min_private_message_post_length) ? "too-short" : "ok";
+    return (messageLength < Discourse.SiteSettings.min_personal_message_post_length) ? "too-short" : "ok";
   },
 
   @computed('message.length')
   customMessageLength(messageLength) {
     const len = messageLength || 0;
-    const minLen = Discourse.SiteSettings.min_private_message_post_length;
+    const minLen = Discourse.SiteSettings.min_personal_message_post_length;
     if (len === 0) {
       return I18n.t("flagging.custom_message.at_least", { count: minLen });
     } else if (len < minLen) {
diff --git a/app/assets/javascripts/discourse/controllers/flag.js.es6 b/app/assets/javascripts/discourse/controllers/flag.js.es6
index e8d309c8c98..87b9daf0012 100644
--- a/app/assets/javascripts/discourse/controllers/flag.js.es6
+++ b/app/assets/javascripts/discourse/controllers/flag.js.es6
@@ -80,7 +80,7 @@ export default Ember.Controller.extend(ModalFunctionality, {
 
     if (selected.get('is_custom_flag')) {
       const len = this.get('message.length') || 0;
-      return len >= Discourse.SiteSettings.min_private_message_post_length &&
+      return len >= Discourse.SiteSettings.min_personal_message_post_length &&
              len <= MAX_MESSAGE_LENGTH;
     }
     return true;
diff --git a/app/assets/javascripts/discourse/models/composer.js.es6 b/app/assets/javascripts/discourse/models/composer.js.es6
index 4cdc2bd4c43..41ec3ba3221 100644
--- a/app/assets/javascripts/discourse/models/composer.js.es6
+++ b/app/assets/javascripts/discourse/models/composer.js.es6
@@ -302,7 +302,7 @@ const Composer = RestModel.extend({
   @computed('privateMessage')
   minimumTitleLength(privateMessage) {
     if (privateMessage) {
-      return this.siteSettings.min_private_message_title_length;
+      return this.siteSettings.min_personal_message_title_length;
     } else {
       return this.siteSettings.min_topic_title_length;
     }
@@ -325,7 +325,7 @@ const Composer = RestModel.extend({
     if (pmWithNonHumanUser) {
       return 1;
     } else if (privateMessage) {
-      return this.siteSettings.min_private_message_post_length;
+      return this.siteSettings.min_personal_message_post_length;
     } else if (topicFirstPost) {
       // first post (topic body)
       return this.siteSettings.min_first_post_length;
diff --git a/app/models/site_setting.rb b/app/models/site_setting.rb
index 46951fa3798..d0ce4465eb4 100644
--- a/app/models/site_setting.rb
+++ b/app/models/site_setting.rb
@@ -38,7 +38,7 @@ class SiteSetting < ActiveRecord::Base
   end
 
   def self.private_message_title_length
-    min_private_message_title_length..max_topic_title_length
+    min_personal_message_title_length..max_topic_title_length
   end
 
   def self.post_length
@@ -50,7 +50,7 @@ class SiteSetting < ActiveRecord::Base
   end
 
   def self.private_message_post_length
-    min_private_message_post_length..max_post_length
+    min_personal_message_post_length..max_post_length
   end
 
   def self.top_menu_items
diff --git a/config/environments/test.rb b/config/environments/test.rb
index 6143f0004a4..8a0fc8c6c99 100644
--- a/config/environments/test.rb
+++ b/config/environments/test.rb
@@ -55,7 +55,7 @@ Discourse::Application.configure do
       s.set_regardless_of_locale(:s3_upload_bucket, 'bucket')
       s.set_regardless_of_locale(:min_post_length, 5)
       s.set_regardless_of_locale(:min_first_post_length, 5)
-      s.set_regardless_of_locale(:min_private_message_post_length, 10)
+      s.set_regardless_of_locale(:min_personal_message_post_length, 10)
       s.set_regardless_of_locale(:crawl_images, false)
       s.set_regardless_of_locale(:download_remote_images_to_local, false)
       s.set_regardless_of_locale(:unique_posts_mins, 0)
diff --git a/config/locales/server.en.yml b/config/locales/server.en.yml
index cce71de7975..d4fe579a123 100644
--- a/config/locales/server.en.yml
+++ b/config/locales/server.en.yml
@@ -970,13 +970,13 @@ en:
     set_locale_from_accept_language_header: "set interface language for anonymous users from their web browser's language headers. (EXPERIMENTAL, does not work with anonymous cache)"
     min_post_length: "Minimum allowed post length in characters"
     min_first_post_length: "Minimum allowed first post (topic body) length in characters"
-    min_private_message_post_length: "Minimum allowed post length in characters for messages"
+    min_personal_message_post_length: "Minimum allowed post length in characters for messages"
     max_post_length: "Maximum allowed post length in characters"
     topic_featured_link_enabled: "Enable posting a link with topics."
     show_topic_featured_link_in_digest: "Show the topic featured link in the digest email."
     min_topic_title_length: "Minimum allowed topic title length in characters"
     max_topic_title_length: "Maximum allowed topic title length in characters"
-    min_private_message_title_length: "Minimum allowed title length for a message in characters"
+    min_personal_message_title_length: "Minimum allowed title length for a message in characters"
     min_search_term_length: "Minimum valid search term length in characters"
     search_tokenize_chinese_japanese_korean: "Force search to tokenize Chinese/Japanese/Korean even on non CJK sites"
     search_prefer_recent_posts: "If searching your large forum is slow, this option tries an index of more recent posts first"
diff --git a/config/site_settings.yml b/config/site_settings.yml
index 8d686b52aed..22bc2846b0d 100644
--- a/config/site_settings.yml
+++ b/config/site_settings.yml
@@ -447,7 +447,7 @@ posting:
     locale_default:
       zh_CN: 8
       zh_TW: 8
-  min_private_message_post_length:
+  min_personal_message_post_length:
     client: true
     min: 1
     default: 10
@@ -490,7 +490,7 @@ posting:
       zh_CN: false
       zh_TW: false
   title_fancy_entities: true
-  min_private_message_title_length:
+  min_personal_message_title_length:
     client: true
     default: 2
     min: 1
diff --git a/db/migrate/20180131052859_rename_private_personal.rb b/db/migrate/20180131052859_rename_private_personal.rb
new file mode 100644
index 00000000000..d1b9dc44677
--- /dev/null
+++ b/db/migrate/20180131052859_rename_private_personal.rb
@@ -0,0 +1,16 @@
+class RenamePrivatePersonal < ActiveRecord::Migration[5.1]
+
+  def setting(old, new)
+    execute "UPDATE site_settings SET name='#{new}' where name='#{old}'"
+  end
+
+  def up
+    setting :min_private_message_post_length, :min_personal_message_post_length
+    setting :min_private_message_title_length, :min_personal_message_title_length
+  end
+
+  def down
+    setting :min_private_message_post_length, :min_personal_message_post_length
+    setting :min_private_message_title_length, :min_personal_message_title_length
+  end
+end
diff --git a/lib/text_sentinel.rb b/lib/text_sentinel.rb
index fa88e647f96..e9b52320041 100644
--- a/lib/text_sentinel.rb
+++ b/lib/text_sentinel.rb
@@ -19,9 +19,9 @@ class TextSentinel
   def self.body_sentinel(text, opts = {})
     entropy = SiteSetting.body_min_entropy
     if opts[:private_message]
-      scale_entropy = SiteSetting.min_private_message_post_length.to_f / SiteSetting.min_post_length.to_f
+      scale_entropy = SiteSetting.min_personal_message_post_length.to_f / SiteSetting.min_post_length.to_f
       entropy = (entropy * scale_entropy).to_i
-      entropy = (SiteSetting.min_private_message_post_length.to_f * ENTROPY_SCALE).to_i if entropy > SiteSetting.min_private_message_post_length
+      entropy = (SiteSetting.min_personal_message_post_length.to_f * ENTROPY_SCALE).to_i if entropy > SiteSetting.min_personal_message_post_length
     else
       entropy = (SiteSetting.min_post_length.to_f * ENTROPY_SCALE).to_i if entropy > SiteSetting.min_post_length
     end
diff --git a/script/import_scripts/base.rb b/script/import_scripts/base.rb
index 7f683818f7a..594579eafe9 100644
--- a/script/import_scripts/base.rb
+++ b/script/import_scripts/base.rb
@@ -71,8 +71,8 @@ class ImportScripts::Base
       min_topic_title_length: 1,
       min_post_length: 1,
       min_first_post_length: 1,
-      min_private_message_post_length: 1,
-      min_private_message_title_length: 1,
+      min_personal_message_post_length: 1,
+      min_personal_message_title_length: 1,
       allow_duplicate_topic_titles: true,
       disable_emails: true,
       max_attachment_size_kb: 102400,
diff --git a/spec/components/text_sentinel_spec.rb b/spec/components/text_sentinel_spec.rb
index 5707fa9895d..e704f6d02ca 100644
--- a/spec/components/text_sentinel_spec.rb
+++ b/spec/components/text_sentinel_spec.rb
@@ -143,7 +143,7 @@ describe TextSentinel do
 
     it "uses a sensible min entropy value when min pm body length is less than min entropy" do
       SiteSetting.min_post_length = 5
-      SiteSetting.min_private_message_post_length = 3
+      SiteSetting.min_personal_message_post_length = 3
       SiteSetting.body_min_entropy = 7
       expect(TextSentinel.body_sentinel('Lol', private_message: true)).to be_valid
     end
diff --git a/spec/components/validators/topic_title_length_validator_spec.rb b/spec/components/validators/topic_title_length_validator_spec.rb
index 58068ae7f2c..dc39cca0eb3 100644
--- a/spec/components/validators/topic_title_length_validator_spec.rb
+++ b/spec/components/validators/topic_title_length_validator_spec.rb
@@ -52,14 +52,14 @@ describe TopicTitleLengthValidator do
   describe 'private message' do
     let(:record) { Fabricate.build(:private_message_topic) }
 
-    it 'adds an error when topic title is shorter than SiteSetting.min_private_message_title_length' do
-      record.title = 'a' * (SiteSetting.min_private_message_title_length - 1)
+    it 'adds an error when topic title is shorter than SiteSetting.min_personal_message_title_length' do
+      record.title = 'a' * (SiteSetting.min_personal_message_title_length - 1)
       validate
       expect(record.errors[:title]).to be_present
     end
 
     it 'does not add an error when topic title is shorter than SiteSetting.min_topic_title_length' do
-      record.title = 'a' * (SiteSetting.min_private_message_title_length)
+      record.title = 'a' * (SiteSetting.min_personal_message_title_length)
       validate
       expect(record.errors[:title]).to_not be_present
     end
diff --git a/spec/models/site_setting_spec.rb b/spec/models/site_setting_spec.rb
index 65907a77a5d..3daaed07f91 100644
--- a/spec/models/site_setting_spec.rb
+++ b/spec/models/site_setting_spec.rb
@@ -26,7 +26,7 @@ describe SiteSetting do
 
   describe 'private_message_title_length' do
     it 'returns a range of min/max pm topic title length' do
-      expect(SiteSetting.private_message_title_length).to eq(SiteSetting.defaults[:min_private_message_title_length]..SiteSetting.defaults[:max_topic_title_length])
+      expect(SiteSetting.private_message_title_length).to eq(SiteSetting.defaults[:min_personal_message_title_length]..SiteSetting.defaults[:max_topic_title_length])
     end
   end
 
diff --git a/spec/models/topic_spec.rb b/spec/models/topic_spec.rb
index 14a42e3406f..a5f61c591d9 100644
--- a/spec/models/topic_spec.rb
+++ b/spec/models/topic_spec.rb
@@ -215,11 +215,11 @@ describe Topic do
   context 'private message title' do
     before do
       SiteSetting.min_topic_title_length = 15
-      SiteSetting.min_private_message_title_length = 3
+      SiteSetting.min_personal_message_title_length = 3
     end
 
     it 'allows shorter titles' do
-      pm = Fabricate.build(:private_message_topic, title: 'a' * SiteSetting.min_private_message_title_length)
+      pm = Fabricate.build(:private_message_topic, title: 'a' * SiteSetting.min_personal_message_title_length)
       expect(pm).to be_valid
     end
 
diff --git a/test/javascripts/models/composer-test.js.es6 b/test/javascripts/models/composer-test.js.es6
index 02475ddb4b6..4add3a84525 100644
--- a/test/javascripts/models/composer-test.js.es6
+++ b/test/javascripts/models/composer-test.js.es6
@@ -38,7 +38,7 @@ QUnit.test('missingReplyCharacters', assert => {
 
   missingReplyCharacters('hi', false, false, Discourse.SiteSettings.min_post_length - 2, 'too short public post');
   missingReplyCharacters('hi', false, true,  Discourse.SiteSettings.min_first_post_length - 2, 'too short first post');
-  missingReplyCharacters('hi', true, false,  Discourse.SiteSettings.min_private_message_post_length - 2, 'too short private message');
+  missingReplyCharacters('hi', true, false,  Discourse.SiteSettings.min_personal_message_post_length - 2, 'too short private message');
 
   const link = "http://imgur.com/gallery/grxX8";
   const composer = createComposer({ canEditTopicFeaturedLink: true, title: link, featuredLink: link, reply: link });
@@ -53,7 +53,7 @@ QUnit.test('missingTitleCharacters', assert => {
   };
 
   missingTitleCharacters('hi', false, Discourse.SiteSettings.min_topic_title_length - 2, 'too short post title');
-  missingTitleCharacters('z', true,  Discourse.SiteSettings.min_private_message_title_length - 1, 'too short pm title');
+  missingTitleCharacters('z', true,  Discourse.SiteSettings.min_personal_message_title_length - 1, 'too short pm title');
 });
 
 QUnit.test('replyDirty', assert => {
@@ -130,7 +130,7 @@ QUnit.test("Title length for regular topics", assert => {
 });
 
 QUnit.test("Title length for private messages", assert => {
-  Discourse.SiteSettings.min_private_message_title_length = 5;
+  Discourse.SiteSettings.min_personal_message_title_length = 5;
   Discourse.SiteSettings.max_topic_title_length = 10;
   const composer = createComposer({action: Composer.PRIVATE_MESSAGE});
 
@@ -145,7 +145,7 @@ QUnit.test("Title length for private messages", assert => {
 });
 
 QUnit.test("Title length for private messages", assert => {
-  Discourse.SiteSettings.min_private_message_title_length = 5;
+  Discourse.SiteSettings.min_personal_message_title_length = 5;
   Discourse.SiteSettings.max_topic_title_length = 10;
   const composer = createComposer({action: Composer.PRIVATE_MESSAGE});