diff --git a/app/logical/post_query_builder.rb b/app/logical/post_query_builder.rb
index 961dfe490..e6a0a7282 100644
--- a/app/logical/post_query_builder.rb
+++ b/app/logical/post_query_builder.rb
@@ -713,7 +713,7 @@ class PostQueryBuilder
         until scanner.eos?
           scanner.skip(/ +/)
 
-          if scanner.scan(/(#{METATAGS.join("|")}):/i)
+          if scanner.scan(/(#{METATAGS.join("|")}):/io)
             metatag = scanner.captures.first
 
             if scanner.scan(/"(.+)"/)
@@ -754,6 +754,10 @@ class PostQueryBuilder
         tags.join(" ")
       end
 
+      def parse_tag_edit(tag_string)
+        split_query(tag_string)
+      end
+
       def parse_query(query, options = {})
         q = {}
 
diff --git a/app/models/post.rb b/app/models/post.rb
index fbda12343..429148ee0 100644
--- a/app/models/post.rb
+++ b/app/models/post.rb
@@ -529,11 +529,11 @@ class Post < ApplicationRecord
 
   module TagMethods
     def tag_array
-      @tag_array ||= PostQueryBuilder.split_query(tag_string)
+      @tag_array ||= tag_string.split
     end
 
     def tag_array_was
-      @tag_array_was ||= PostQueryBuilder.split_query(tag_string_in_database.presence || tag_string_before_last_save || "")
+      @tag_array_was ||= (tag_string_in_database.presence || tag_string_before_last_save || "").split
     end
 
     def tags
@@ -595,9 +595,9 @@ class Post < ApplicationRecord
       if old_tag_string
         # If someone else committed changes to this post before we did,
         # then try to merge the tag changes together.
-        current_tags = tag_array_was
-        new_tags = tag_array
-        old_tags = PostQueryBuilder.split_query(old_tag_string)
+        current_tags = tag_string_was.split
+        new_tags = PostQueryBuilder.parse_tag_edit(tag_string)
+        old_tags = old_tag_string.split
 
         kept_tags = current_tags & new_tags
         @removed_tags = old_tags - kept_tags