diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/ubuntu.yml
index 03ffb5b09..21ab4c2d7 100644
--- a/.github/workflows/ubuntu.yml
+++ b/.github/workflows/ubuntu.yml
@@ -66,7 +66,8 @@ jobs:
         run: cmake --build build --target ${{ matrix.target }}
 
   ci_cmake_flags:
-    runs-on: ubuntu-focal
+    runs-on: ubuntu-latest
+    container: ubuntu:focal
     steps:
       - uses: actions/checkout@v3
       - name: Get latest CMake and ninja
diff --git a/nlohmann_json.natvis b/nlohmann_json.natvis
index b101771e6..a831ea04b 100644
--- a/nlohmann_json.natvis
+++ b/nlohmann_json.natvis
@@ -1,7 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+
 <!-- * * * * * * * * AUTO-GENERATED FILE  * * * * * * * * -->
 <!-- Edit ./tools/generate_natvis/nlohmann_json.natvis.j2 -->
 <!-- * * * * * * * * AUTO-GENERATED FILE  * * * * * * * * -->
-<?xml version="1.0" encoding="utf-8"?>
+
 <AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
     <!-- Namespace nlohmann -->
     <Type Name="nlohmann::basic_json&lt;*&gt;">
diff --git a/tools/generate_natvis/nlohmann_json.natvis.j2 b/tools/generate_natvis/nlohmann_json.natvis.j2
index 0a9ee2ce2..d6b728935 100644
--- a/tools/generate_natvis/nlohmann_json.natvis.j2
+++ b/tools/generate_natvis/nlohmann_json.natvis.j2
@@ -1,7 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+
 <!-- * * * * * * * * AUTO-GENERATED FILE  * * * * * * * * -->
 <!-- Edit ./tools/generate_natvis/nlohmann_json.natvis.j2 -->
 <!-- * * * * * * * * AUTO-GENERATED FILE  * * * * * * * * -->
-<?xml version="1.0" encoding="utf-8"?>
+
 <AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
 {% for ns in namespaces %}
     <!-- Namespace {{ ns }} -->