diff --git a/app/models/optimized_image.rb b/app/models/optimized_image.rb
index 5e5e8e41919..5cc24846543 100644
--- a/app/models/optimized_image.rb
+++ b/app/models/optimized_image.rb
@@ -7,7 +7,7 @@ class OptimizedImage < ActiveRecord::Base
   belongs_to :upload
 
   # BUMP UP if optimized image algorithm changes
-  VERSION = 1
+  VERSION = 2
 
   def self.lock(upload_id, width, height)
     @hostname ||= `hostname`.strip rescue "unknown"
@@ -43,7 +43,7 @@ class OptimizedImage < ActiveRecord::Base
     thumbnail = find_by(upload_id: upload.id, width: width, height: height)
 
     # correct bad thumbnail if needed
-    if thumbnail && thumbnail.url.blank?
+    if thumbnail && (thumbnail.url.blank? || thumbnail.version != VERSION)
       thumbnail.destroy!
       thumbnail = nil
     end
@@ -94,7 +94,8 @@ class OptimizedImage < ActiveRecord::Base
             width: width,
             height: height,
             url: "",
-            filesize: File.size(temp_path)
+            filesize: File.size(temp_path),
+            version: VERSION
           )
 
           # store the optimized image and update its url
diff --git a/db/migrate/20190103051737_add_version_to_optimized_images.rb b/db/migrate/20190103051737_add_version_to_optimized_images.rb
new file mode 100644
index 00000000000..88d2fb99586
--- /dev/null
+++ b/db/migrate/20190103051737_add_version_to_optimized_images.rb
@@ -0,0 +1,5 @@
+class AddVersionToOptimizedImages < ActiveRecord::Migration[5.2]
+  def change
+    add_column :optimized_images, :version, :integer
+  end
+end
diff --git a/spec/models/optimized_image_spec.rb b/spec/models/optimized_image_spec.rb
index 35e95cd9be7..4c832a8f4bf 100644
--- a/spec/models/optimized_image_spec.rb
+++ b/spec/models/optimized_image_spec.rb
@@ -201,6 +201,32 @@ describe OptimizedImage do
 
   describe ".create_for" do
 
+    context "versioning" do
+      let(:filename) { 'logo.png' }
+      let(:file) { file_from_fixtures(filename) }
+
+      it "is able to update optimized images on version change" do
+        upload = UploadCreator.new(file, filename).create_for(Discourse.system_user.id)
+        optimized = OptimizedImage.create_for(upload, 10, 10)
+
+        expect(optimized.version).to eq(OptimizedImage::VERSION)
+
+        optimized_again = OptimizedImage.create_for(upload, 10, 10)
+        expect(optimized_again.id).to eq(optimized.id)
+
+        optimized.update_columns(version: nil)
+        old_id = optimized.id
+
+        optimized_new = OptimizedImage.create_for(upload, 10, 10)
+
+        expect(optimized_new.id).not_to eq(old_id)
+
+        # cleanup (which transaction rollback may miss)
+        optimized_new.destroy
+        upload.destroy
+      end
+    end
+
     it "is able to 'optimize' an svg" do
       # we don't really optimize anything, we simply copy
       # but at least this confirms this actually works