diff --git a/activestorage/app/controllers/active_storage/blobs/proxy_controller.rb b/activestorage/app/controllers/active_storage/blobs/proxy_controller.rb
index cc90c6b94b..7e43b60403 100644
--- a/activestorage/app/controllers/active_storage/blobs/proxy_controller.rb
+++ b/activestorage/app/controllers/active_storage/blobs/proxy_controller.rb
@@ -17,7 +17,7 @@ class ActiveStorage::Blobs::ProxyController < ActiveStorage::BaseController
         response.headers["Accept-Ranges"] = "bytes"
         response.headers["Content-Length"] = @blob.byte_size.to_s
 
-        send_blob_stream @blob
+        send_blob_stream @blob, disposition: params[:disposition]
       end
     end
   end
diff --git a/activestorage/app/controllers/active_storage/representations/proxy_controller.rb b/activestorage/app/controllers/active_storage/representations/proxy_controller.rb
index c31c7bd4a4..7e98c2184f 100644
--- a/activestorage/app/controllers/active_storage/representations/proxy_controller.rb
+++ b/activestorage/app/controllers/active_storage/representations/proxy_controller.rb
@@ -9,7 +9,7 @@
 class ActiveStorage::Representations::ProxyController < ActiveStorage::Representations::BaseController
   def show
     http_cache_forever public: true do
-      send_blob_stream @representation.image
+      send_blob_stream @representation.image, disposition: params[:disposition]
     end
   end
 end
diff --git a/activestorage/test/controllers/blobs/proxy_controller_test.rb b/activestorage/test/controllers/blobs/proxy_controller_test.rb
index 83bcf3f0f8..443539aded 100644
--- a/activestorage/test/controllers/blobs/proxy_controller_test.rb
+++ b/activestorage/test/controllers/blobs/proxy_controller_test.rb
@@ -21,11 +21,17 @@ class ActiveStorage::Blobs::ProxyControllerTest < ActionDispatch::IntegrationTes
     assert_equal "application/octet-stream", response.headers["Content-Type"]
   end
 
-  test "forcing Content-Disposition to attachment" do
+  test "forcing Content-Disposition to attachment based on type" do
     get rails_storage_proxy_url(create_blob(content_type: "application/zip"))
     assert_match(/^attachment; /, response.headers["Content-Disposition"])
   end
 
+  test "caller can change disposition to attachment" do
+    url = rails_storage_proxy_url(create_blob(content_type: "image/jpeg"), disposition: :attachment)
+    get url
+    assert_match(/^attachment; /, response.headers["Content-Disposition"])
+  end
+
   test "signed ID within expiration date" do
     get rails_storage_proxy_url(create_file_blob(filename: "racecar.jpg"), expires_in: 1.minute)
     assert_response :success
diff --git a/activestorage/test/controllers/representations/proxy_controller_test.rb b/activestorage/test/controllers/representations/proxy_controller_test.rb
index 8ae815ea1d..67665e99db 100644
--- a/activestorage/test/controllers/representations/proxy_controller_test.rb
+++ b/activestorage/test/controllers/representations/proxy_controller_test.rb
@@ -8,6 +8,22 @@ class ActiveStorage::Representations::ProxyControllerWithVariantsTest < ActionDi
     @blob = create_file_blob filename: "racecar.jpg"
   end
 
+  test "showing variant attachment" do
+    get rails_blob_representation_proxy_url(
+      disposition: :attachment,
+      filename: @blob.filename,
+      signed_blob_id: @blob.signed_id,
+      variation_key: ActiveStorage::Variation.encode(resize_to_limit: [100, 100]))
+
+    assert_response :ok
+    assert_match(/^attachment/, response.headers["Content-Disposition"])
+
+    image = read_image(@blob.variant(resize_to_limit: [100, 100]))
+    assert_equal 100, image.width
+    assert_equal 67, image.height
+  end
+
+
   test "showing variant inline" do
     get rails_blob_representation_proxy_url(
       filename: @blob.filename,