diff --git a/src/main/Program.cs b/src/main/Program.cs
index 9d89a00..966e9e7 100644
--- a/src/main/Program.cs
+++ b/src/main/Program.cs
@@ -41,7 +41,7 @@ class Program {
                     byte[] fileData = azp.GetFileBytes(internalPath.TrimStart('/'));
                     return fileData != null ? new MemoryStream(fileData) : null;
                 }
-                contentType = null;
+                contentType = null!;
                 return null;
             });