diff --git a/src/Microsoft.Tye.Core/ProjectReader.cs b/src/Microsoft.Tye.Core/ProjectReader.cs
index 745308fb..7b41cbe0 100644
--- a/src/Microsoft.Tye.Core/ProjectReader.cs
+++ b/src/Microsoft.Tye.Core/ProjectReader.cs
@@ -62,7 +62,7 @@ namespace Microsoft.Tye
                 throw new ArgumentNullException(nameof(project));
             }
 
-            if (project is null)
+            if (metadataFile is null)
             {
                 throw new ArgumentNullException(nameof(metadataFile));
             }