diff --git a/tests/Jellyfin.Plugin.AetherAnalysis.Tests/Jellyfin.Plugin.AetherAnalysis.Tests.csproj b/tests/Jellyfin.Plugin.AetherAnalysis.Tests/Jellyfin.Plugin.AetherAnalysis.Tests.csproj
index 4e9cb5a..469c010 100644
--- a/tests/Jellyfin.Plugin.AetherAnalysis.Tests/Jellyfin.Plugin.AetherAnalysis.Tests.csproj
+++ b/tests/Jellyfin.Plugin.AetherAnalysis.Tests/Jellyfin.Plugin.AetherAnalysis.Tests.csproj
@@ -10,7 +10,7 @@
     <PackageReference Include="Jellyfin.Model" Version="10.11.11" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.8.1" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite.Core" Version="9.0.11" />
-    <PackageReference Include="NSubstitute" Version="5.3.0" />
+    <PackageReference Include="NSubstitute" Version="6.0.0" />
     <!-- Tests run outside Jellyfin and therefore supply their own patched
          native SQLite runtime. This package is intentionally test-only. -->
     <PackageReference Include="SQLitePCLRaw.bundle_e_sqlite3" Version="3.0.3" />
diff --git a/tests/Jellyfin.Plugin.AetherAnalysis.Tests/packages.lock.json b/tests/Jellyfin.Plugin.AetherAnalysis.Tests/packages.lock.json
index 41a6321..527eedd 100644
--- a/tests/Jellyfin.Plugin.AetherAnalysis.Tests/packages.lock.json
+++ b/tests/Jellyfin.Plugin.AetherAnalysis.Tests/packages.lock.json
@@ -115,9 +115,9 @@
       },
       "NSubstitute": {
         "type": "Direct",
-        "requested": "[5.3.0, )",
-        "resolved": "5.3.0",
-        "contentHash": "lJ47Cps5Qzr86N99lcwd+OUvQma7+fBgr8+Mn+aOC0WrlqMNkdivaYD9IvnZ5Mqo6Ky3LS7ZI+tUq1/s9ERd0Q==",
+        "requested": "[6.0.0, )",
+        "resolved": "6.0.0",
+        "contentHash": "0gvKMbiJ+/WrfbcfBfqRZZrvfLJcd3rqkqVMjjlY5dtmLRVzMY+o/K/rJUStofQ2haSr9Vd04YDfvZtVVGS3/A==",
         "dependencies": {
           "Castle.Core": "5.1.1"
         }