diff --git a/.github/workflows/create-unitypackage.yml b/.github/workflows/create-unitypackage.yml
index a67ef89cb9..a3bf2e3efc 100644
--- a/.github/workflows/create-unitypackage.yml
+++ b/.github/workflows/create-unitypackage.yml
@@ -92,7 +92,7 @@ jobs:
   create-unitypackage:
     needs: [detect-unity-version, run-edit-mode-tests]
     runs-on: [self-hosted, Windows, X64, Unity]
-    timeout-minutes: 10
+    timeout-minutes: 20
     steps:
     - name: Create UnityPackage
       id: create-unitypackage
@@ -103,6 +103,7 @@ jobs:
           -projectPath "${UNITY_PROJECT_PATH}" \
           -executeMethod "VRM.DevOnly.PackageExporter.VRMExportUnityPackage.CreateUnityPackageWithBuild" \
           -logFile create-unitypackage.log
+
     - name: Upload UnityPackage
       uses: actions/upload-artifact@v4
       with:
diff --git a/Assets/VRM/Editor/VRMExportUnityPackage.cs b/Assets/VRM/Editor/VRMExportUnityPackage.cs
index 6f642c1770..1ad482342c 100644
--- a/Assets/VRM/Editor/VRMExportUnityPackage.cs
+++ b/Assets/VRM/Editor/VRMExportUnityPackage.cs
@@ -22,6 +22,9 @@ public static bool EndsWithAndMeta(this string str, string terminator)
         }
     }
 
+    /// <summary>
+    /// TODO: 本来このクラスは「パッケージとしての UniVRM」のスコープのクラスであるが、「UPM Package VRM」のスコープにコードがあるので変
+    /// </summary>
     public static class VRMExportUnityPackage
     {
         static string GetProjectRoot()
@@ -142,18 +145,20 @@ public static void CreateUnityPackageWithBuild()
         {
             try
             {
+                Debug.Log($"[{nameof(VRMExportUnityPackage)}] Start CreateUnityPackageWithBuild...");
                 var folder = GetProjectRoot();
                 if (!Directory.Exists(folder))
                 {
                     Directory.CreateDirectory(folder);
                 }
 
-                if (!BuildTestScene())
-                {
-                    throw new Exception("Failed to build test scenes");
-                }
+                Debug.Log($"[{nameof(VRMExportUnityPackage)}] Try to build test scenes...");
+                BuildTestScene();
+
+                Debug.Log($"[{nameof(VRMExportUnityPackage)}] Create UnityPackages...");
                 CreateUnityPackages(folder);
 
+                Debug.Log($"[{nameof(VRMExportUnityPackage)}] Finish CreateUnityPackageWithBuild");
                 if (Application.isBatchMode)
                 {
                     EditorApplication.Exit(0);
@@ -201,7 +206,7 @@ public PackageInfo(string name)
             }
         }
 
-        public static void CreateUnityPackages(string outputDir)
+        private static void CreateUnityPackages(string outputDir)
         {
             if (!VRMSampleCopy.Validate())
             {
@@ -250,7 +255,7 @@ public static void CreateUnityPackages(string outputDir)
             }
         }
 
-        public static void CreateUnityPackage(
+        private static void CreateUnityPackage(
             string outputDir,
             PackageInfo package
             )
@@ -264,13 +269,18 @@ PackageInfo package
             AssetDatabase.ExportPackage(targetFileNames, path, ExportPackageOptions.Default);
         }
 
-        public static bool BuildTestScene()
+        private static void BuildTestScene()
         {
-            var levels = new string[] { "Assets/VRM.Samples/Scenes/VRMRuntimeLoaderSample.unity" };
-            return Build(levels);
+            var levels = new string[]
+            {
+                "Assets/UniGLTF_Samples/GltfViewer/GltfViewer.unity",
+                "Assets/VRM_Samples/SimpleViewer/SimpleViewer.unity",
+                "Assets/VRM10_Samples/VRM10Viewer/VRM10Viewer.unity",
+            };
+            Build(levels);
         }
 
-        public static bool Build(string[] levels)
+        private static void Build(string[] levels)
         {
             var buildPath = Path.GetFullPath(Application.dataPath + "/../build/build.exe");
             Debug.LogFormat("BuildPath: {0}", buildPath);
@@ -279,12 +289,10 @@ public static bool Build(string[] levels)
                 BuildTarget.StandaloneWindows,
                 BuildOptions.None
             );
-#if UNITY_2018_1_OR_NEWER
-            var isSuccess = build.summary.result == BuildResult.Succeeded;
-#else
-            var isSuccess = !string.IsNullOrEmpty(build);
-#endif
-            return isSuccess;
+            if (build.summary.result != BuildResult.Succeeded)
+            {
+                throw new Exception("Failed to build scenes");
+            }
         }
     }
 }