diff --git a/.gitea/workflows/ci.yml b/.gitea/workflows/ci.yml
index 28ce98e..2e674f6 100644
--- a/.gitea/workflows/ci.yml
+++ b/.gitea/workflows/ci.yml
@@ -15,11 +15,13 @@ jobs:
     timeout-minutes: 45
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+      - name: Validate runner architecture
+        run: test "$(uname -m)" = "x86_64"
       - name: Build validation image
-        run: docker buildx build --platform linux/amd64 --file tests/Dockerfile.ci --load --tag homeassistant-stelloauth-tests:test .
+        run: docker build --file tests/Dockerfile.ci --tag homeassistant-stelloauth-tests:test .
       - name: Validate metadata, patches, and process manager
         run: docker run --rm homeassistant-stelloauth-tests:test -q
       - name: Build amd64 image
-        run: docker buildx build --platform linux/amd64 --build-arg BUILD_ARCH=amd64 --load --tag homeassistant-stelloauth-addon:test stelloauth
+        run: docker build --build-arg TARGETARCH=amd64 --build-arg BUILD_ARCH=amd64 --tag homeassistant-stelloauth-addon:test stelloauth
       - name: Exercise runtime
         run: SKIP_BUILD=1 tests/test_runtime.sh
diff --git a/tests/test_addon_metadata.py b/tests/test_addon_metadata.py
index d3304ea..261438d 100644
--- a/tests/test_addon_metadata.py
+++ b/tests/test_addon_metadata.py
@@ -147,18 +147,20 @@ def test_ci_builds_and_loads_only_the_amd64_test_image() -> None:
     workflow = (ROOT / ".gitea/workflows/ci.yml").read_text(encoding="utf-8")
     parsed = yaml.safe_load(workflow)
     steps = parsed["jobs"]["validate"]["steps"]
+    architecture_command = next(
+        step["run"] for step in steps if step.get("name") == "Validate runner architecture"
+    )
+    assert architecture_command == 'test "$(uname -m)" = "x86_64"'
     build_command = next(
         step["run"] for step in steps if step.get("name") == "Build amd64 image"
     )
     assert build_command.split() == [
         "docker",
-        "buildx",
         "build",
-        "--platform",
-        "linux/amd64",
+        "--build-arg",
+        "TARGETARCH=amd64",
         "--build-arg",
         "BUILD_ARCH=amd64",
-        "--load",
         "--tag",
         "homeassistant-stelloauth-addon:test",
         "stelloauth",
@@ -184,13 +186,9 @@ def test_ci_runs_validation_in_pinned_container() -> None:
     )
     assert build_command.split() == [
         "docker",
-        "buildx",
         "build",
-        "--platform",
-        "linux/amd64",
         "--file",
         "tests/Dockerfile.ci",
-        "--load",
         "--tag",
         "homeassistant-stelloauth-tests:test",
         ".",