diff --git a/lsp/src/main/java/workspace/LSPWorkspaceManager.java b/lsp/src/main/java/workspace/LSPWorkspaceManager.java
index 056e21df9..f8cd408c2 100644
--- a/lsp/src/main/java/workspace/LSPWorkspaceManager.java
+++ b/lsp/src/main/java/workspace/LSPWorkspaceManager.java
@@ -543,6 +543,7 @@ private void loadExternalFile(File file) throws IOException
 				source.printSource(spw);
 				spw.close();
 				Diag.info("Extracted source written to " + extract);
+				extract.setReadOnly();	// Works with files.readonlyFromPermissions in VSCode
 				
 				loadFile(extract);