diff --git a/lib/ammoprices_web/live/caliber_live/show.ex b/lib/ammoprices_web/live/caliber_live/show.ex
index 7c207d0..f35e2f7 100644
--- a/lib/ammoprices_web/live/caliber_live/show.ex
+++ b/lib/ammoprices_web/live/caliber_live/show.ex
@@ -282,6 +282,7 @@ defmodule AmmopricesWeb.CaliberLive.Show do
           <div
             id="price-chart-container"
             phx-hook=".PriceChart"
+            phx-update="ignore"
             data-chart-data={Jason.encode!(@chart_data)}
             class="h-64 sm:h-80"
           >
diff --git a/test/ammoprices_web/live/caliber_live/show_test.exs b/test/ammoprices_web/live/caliber_live/show_test.exs
index 31aaa8e..5fc4840 100644
--- a/test/ammoprices_web/live/caliber_live/show_test.exs
+++ b/test/ammoprices_web/live/caliber_live/show_test.exs
@@ -182,6 +182,22 @@ defmodule AmmopricesWeb.CaliberLive.ShowTest do
       assert has_element?(view, "#filter-casing-steel")
     end
 
+    test "chart container uses phx-update=ignore to survive DOM patches", %{
+      conn: conn,
+      caliber: caliber,
+      retailer: retailer
+    } do
+      now = DateTime.truncate(DateTime.utc_now(), :second)
+      product = product_fixture(%{caliber: caliber, retailer: retailer, grain_weight: 115, in_stock: true})
+      snapshot_fixture(%{product: product, price_per_round_cents: 28, in_stock: true, recorded_at: now})
+
+      {:ok, view, _html} = live(conn, "/calibers/#{caliber.slug}")
+
+      # Chart container must have phx-update="ignore" so LiveView
+      # does not replace the canvas element managed by Chart.js
+      assert has_element?(view, "#price-chart-container[phx-update=ignore]")
+    end
+
     test "receives real-time price updates via PubSub", %{conn: conn, caliber: caliber, retailer: retailer} do
       now = DateTime.truncate(DateTime.utc_now(), :second)
       product = product_fixture(%{caliber: caliber, retailer: retailer, in_stock: true})