diff --git a/src/LfMerge.Core.Tests/SRTestEnvironment.cs b/src/LfMerge.Core.Tests/SRTestEnvironment.cs
index 0011b5c9..350321ed 100644
--- a/src/LfMerge.Core.Tests/SRTestEnvironment.cs
+++ b/src/LfMerge.Core.Tests/SRTestEnvironment.cs
@@ -178,7 +178,7 @@ public async Task TusUpload(Uri tusEndpoint, string path, string mimeType)
 			var createResponse = await Http.TusCreateAsync(createOpts);
 
 			// That doesn't actually upload the file; TusPatchAsync does the actual upload
-			var fileStream = new FileStream(file.FullName, FileMode.Open, FileAccess.Read);
+			using var fileStream = new FileStream(file.FullName, FileMode.Open, FileAccess.Read);
 			var patchOpts = new TusPatchRequestOption {
 				FileLocation = createResponse.FileLocation,
 				Stream = fileStream,