diff --git a/.github/workflows/pytest.yaml b/.github/workflows/pytest.yaml
index fb25eff0..21d76466 100644
--- a/.github/workflows/pytest.yaml
+++ b/.github/workflows/pytest.yaml
@@ -26,7 +26,17 @@ jobs:
             python-version: "3.13"
           - core-version: "2025.5.3"
             python-version: "3.13"
-          - core-version: "2025.6.1"
+          - core-version: "2025.6.3"
+            python-version: "3.13"
+          - core-version: "2025.7.4"
+            python-version: "3.13"
+          - core-version: "2025.8.3"
+            python-version: "3.13"
+          - core-version: "2025.9.4"
+            python-version: "3.13"
+          - core-version: "2025.10.4"
+            python-version: "3.13"
+          - core-version: "2025.11.3"
             python-version: "3.13"
           - core-version: "dev"
             python-version: "3.13"
diff --git a/Dockerfile b/Dockerfile
index 3bd36ddd..c4d9c695 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -9,6 +9,12 @@
 
 FROM ghcr.io/astral-sh/uv:debian
 
+# Install build dependencies for Python extensions
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    python3-dev \
+    build-essential \
+    && rm -rf /var/lib/apt/lists/*
+
 # Clone home-assistant/core
 RUN git clone --depth 1 --branch dev https://github.com/home-assistant/core.git /core
 
diff --git a/custom_components/adaptive_lighting/manifest.json b/custom_components/adaptive_lighting/manifest.json
index 92100afa..856abfe8 100644
--- a/custom_components/adaptive_lighting/manifest.json
+++ b/custom_components/adaptive_lighting/manifest.json
@@ -8,5 +8,5 @@
   "iot_class": "calculated",
   "issue_tracker": "https://github.com/basnijholt/adaptive-lighting/issues",
   "requirements": ["ulid-transform"],
-  "version": "1.26.0"
+  "version": "1.27.0"
 }
diff --git a/scripts/setup-dependencies b/scripts/setup-dependencies
index b9e2de1f..92a41411 100755
--- a/scripts/setup-dependencies
+++ b/scripts/setup-dependencies
@@ -6,6 +6,22 @@ if grep -q 'mypy-dev==1.14.0a3' core/requirements_test.txt; then
     # mypy-dev==1.14.0a3 seems to not be available anymore, HA 2024.12 is affected
     sed -i 's/mypy-dev==1.14.0a3/mypy-dev==1.14.0a7/' core/requirements_test.txt
 fi
+if grep -q 'mypy-dev==1.16.0a1' core/requirements_test.txt; then
+    # mypy-dev==1.16.0a1 seems to not be available anymore, HA 2025.2 is affected
+    sed -i 's/mypy-dev==1.16.0a1/mypy-dev==1.16.0a9/' core/requirements_test.txt
+fi
+if grep -q 'mypy-dev==1.16.0a3' core/requirements_test.txt; then
+    # mypy-dev==1.16.0a3 seems to not be available anymore, HA 2025.3 is affected
+    sed -i 's/mypy-dev==1.16.0a3/mypy-dev==1.16.0a9/' core/requirements_test.txt
+fi
+if grep -q 'mypy-dev==1.16.0a7' core/requirements_test.txt; then
+    # mypy-dev==1.16.0a7 seems to not be available anymore, HA 2025.4 is affected
+    sed -i 's/mypy-dev==1.16.0a7/mypy-dev==1.16.0a9/' core/requirements_test.txt
+fi
+if grep -q 'mypy-dev==1.16.0a8' core/requirements_test.txt; then
+    # mypy-dev==1.16.0a8 seems to not be available anymore, HA 2025.5 and 2025.6 is affected
+    sed -i 's/mypy-dev==1.16.0a8/mypy-dev==1.16.0a9/' core/requirements_test.txt
+fi
 
 uv pip install -r core/requirements.txt
 uv pip install -r core/requirements_test.txt
diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 00000000..cce77d96
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,26 @@
+"""Pytest configuration for adaptive-lighting tests."""
+
+from unittest.mock import patch
+
+import pytest
+
+
+@pytest.fixture(autouse=True)
+def mock_template_deprecation_issue():
+    """Mock the template deprecation issue creation.
+
+    The template component's legacy platform syntax creates deprecation
+    issues that require translations. Since adaptive-lighting tests use
+    template lights as test fixtures (not testing the template integration
+    itself), we mock the issue creation to avoid translation validation errors.
+    """
+    # Patch the create_legacy_template_issue function in the template helpers
+    # to be a no-op when called for the deprecated_legacy_templates issue
+    try:
+        with patch(
+            "homeassistant.components.template.helpers.create_legacy_template_issue",
+        ):
+            yield
+    except (ImportError, ModuleNotFoundError, AttributeError):
+        # Older HA versions don't have this function
+        yield
diff --git a/tests/test_switch.py b/tests/test_switch.py
index cc03fa24..fc5f67cc 100644
--- a/tests/test_switch.py
+++ b/tests/test_switch.py
@@ -82,7 +82,16 @@ from homeassistant.components.light import (
 )
 from homeassistant.components.light import DOMAIN as LIGHT_DOMAIN
 from homeassistant.components.switch import DOMAIN as SWITCH_DOMAIN
-from homeassistant.components.template.light import LightTemplate
+
+try:
+    # HA >= 2025.8
+    from homeassistant.components.template.light import (
+        StateLightEntity as LightTemplate,
+    )
+except ImportError:
+    # HA < 2025.8
+    from homeassistant.components.template.light import LightTemplate
+
 from homeassistant.config_entries import ConfigEntryState
 from homeassistant.const import (
     ATTR_AREA_ID,