diff --git a/app/models/post.rb b/app/models/post.rb
index 75e34e0ff..c0fb63200 100644
--- a/app/models/post.rb
+++ b/app/models/post.rb
@@ -225,7 +225,7 @@ class Post < ActiveRecord::Base
     end
     
     def remove_favorite(user)
-      self.fav_string.gsub!(/fav:#{user.name}\b\s*/, " ")
+      self.fav_string.gsub!(/(?:\A| )fav:#{user.name}(?:\Z| )/, " ")
       self.fav_string.strip!
       Favorite.destroy(user, self)
     end
@@ -454,7 +454,7 @@ class Post < ActiveRecord::Base
     end
     
     def remove_pool(pool)
-      self.pool_string.gsub!(/pool:#{pool.name}\b\s*/, " ")
+      self.pool_string.gsub!(/(?:\A| )pool:#{pool.name}(?:\Z| )/, " ")
       self.pool_string.strip!
     end
   end
diff --git a/app/models/tag_alias.rb b/app/models/tag_alias.rb
index ea69ba203..2e5415eca 100644
--- a/app/models/tag_alias.rb
+++ b/app/models/tag_alias.rb
@@ -40,7 +40,7 @@ class TagAlias < ActiveRecord::Base
   def update_posts
     Post.find_by_tags(antecedent_name).find_each do |post|
       escaped_antecedent_name = Regexp.escape(antecedent_name)
-      fixed_tags = post.tag_string.sub(/\A#{escaped_antecedent_name} | #{escaped_antecedent_name} | #{escaped_antecedent_name}\Z/, " #{consequent_name} ").strip
+      fixed_tags = post.tag_string.sub(/(?:\A| )#{escaped_antecedent_name}(?:\Z| )/, " #{consequent_name} ").strip
       post.update_attributes(
         :tag_string => fixed_tags,
         :updater_id => updater_id,
diff --git a/app/models/tag_implication.rb b/app/models/tag_implication.rb
index b5c793519..1b44a318e 100644
--- a/app/models/tag_implication.rb
+++ b/app/models/tag_implication.rb
@@ -69,7 +69,7 @@ class TagImplication < ActiveRecord::Base
   def update_posts
     Post.find_by_tags(antecedent_name).find_each do |post|
       escaped_antecedent_name = Regexp.escape(antecedent_name)
-      fixed_tags = post.tag_string.sub(/\A#{escaped_antecedent_name} | #{escaped_antecedent_name} | #{escaped_antecedent_name}\Z/, " #{antecedent_name} #{descendant_names} ").strip
+      fixed_tags = post.tag_string.sub(/(?:\A| )#{escaped_antecedent_name}(?:\Z| )/, " #{antecedent_name} #{descendant_names} ").strip
       post.update_attributes(
         :tag_string => fixed_tags,
         :updater_id => updater_id,