diff --git a/lib/stimulus_reflex/reflex_data.rb b/lib/stimulus_reflex/reflex_data.rb
index f8b3af20..acd7e676 100644
--- a/lib/stimulus_reflex/reflex_data.rb
+++ b/lib/stimulus_reflex/reflex_data.rb
@@ -52,7 +52,7 @@ def form_data
   end
 
   def params
-    form_params.merge(url_params)
+    form_params.deep_merge(url_params)
   end
 
   def form_params
diff --git a/test/reflex_data_test.rb b/test/reflex_data_test.rb
new file mode 100644
index 00000000..7aa93bcb
--- /dev/null
+++ b/test/reflex_data_test.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+require_relative "test_helper"
+
+class StimulusReflex::ReflexDataTest < ActiveSupport::TestCase
+  reflex_data = StimulusReflex::ReflexData.new({
+    "params" => {
+      "user" => {"email" => "test@example.com"}
+    },
+    "url" => "http://example.com/?user[context]=regular"
+  })
+
+  test "accessing form_params keeps url_params with the same keys" do
+    assert_equal "regular", reflex_data.params["user"]["context"]
+    assert_equal "test@example.com", reflex_data.params["user"]["email"]
+  end
+end