diff --git a/config/locales/server.en.yml b/config/locales/server.en.yml
index c934b49568f..abbdc770e53 100644
--- a/config/locales/server.en.yml
+++ b/config/locales/server.en.yml
@@ -1510,9 +1510,9 @@ en:
     allow_user_locale: "Allow users to choose their own language interface preference"
     set_locale_from_accept_language_header: "set interface language for anonymous users from their web browser's language headers"
     support_mixed_text_direction: "Support mixed left-to-right and right-to-left text directions."
-    min_post_length: "Minimum allowed post length in characters"
-    min_first_post_length: "Minimum allowed first post (topic body) length in characters"
-    min_personal_message_post_length: "Minimum allowed post length in characters for messages"
+    min_post_length: "Minimum allowed post length in characters (excluding personal messages)"
+    min_first_post_length: "Minimum allowed first post (topic body) length (excluding personal messages)"
+    min_personal_message_post_length: "Minimum allowed post length in characters for messages (both first post and replies)"
     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."
diff --git a/lib/post_creator.rb b/lib/post_creator.rb
index f1afa7aac72..787787b2edc 100644
--- a/lib/post_creator.rb
+++ b/lib/post_creator.rb
@@ -167,7 +167,11 @@ class PostCreator
     DiscourseEvent.trigger :before_create_post, @post, @opts
     DiscourseEvent.trigger :validate_post, @post
 
-    post_validator = PostValidator.new(skip_topic: true)
+    post_validator =
+      PostValidator.new(
+        skip_topic: true,
+        private_message: @opts[:archetype] == Archetype.private_message,
+      )
     post_validator.validate(@post)
 
     valid = @post.errors.blank?
diff --git a/lib/validators/post_validator.rb b/lib/validators/post_validator.rb
index 737c37c1dbf..766424d13bd 100644
--- a/lib/validators/post_validator.rb
+++ b/lib/validators/post_validator.rb
@@ -212,7 +212,7 @@ class PostValidator < ActiveModel::Validator
   end
 
   def private_message?(post)
-    post.topic.try(:private_message?)
+    post.topic.try(:private_message?) || options[:private_message]
   end
 
   def add_error_if_count_exceeded(
diff --git a/spec/lib/post_creator_spec.rb b/spec/lib/post_creator_spec.rb
index 4dc8bdde0d1..b2209df8e2d 100644
--- a/spec/lib/post_creator_spec.rb
+++ b/spec/lib/post_creator_spec.rb
@@ -208,7 +208,6 @@ RSpec.describe PostCreator do
         cat.save
 
         created_post = nil
-        other_user_tracking_topic = nil
 
         messages =
           MessageBus.track_publish do
@@ -1099,6 +1098,26 @@ RSpec.describe PostCreator do
       )
     end
 
+    it "respects min_personal_message_post_length" do
+      SiteSetting.min_personal_message_post_length = 5
+      SiteSetting.min_first_post_length = 20
+      SiteSetting.min_post_length = 25
+      SiteSetting.body_min_entropy = 20
+      user.update!(trust_level: 3)
+      Group.refresh_automatic_groups!
+
+      expect {
+        PostCreator.create!(
+          user,
+          title: "hi there welcome to my PM",
+          raw: "sorry",
+          archetype: Archetype.private_message,
+          target_usernames: [target_user1.username, target_user2.username].join(","),
+          category: 1,
+        )
+      }.not_to raise_error
+    end
+
     it "acts correctly" do
       freeze_time