diff --git a/packages/myst-cli/src/process/file.ts b/packages/myst-cli/src/process/file.ts
index a56aea658..73d5a656c 100644
--- a/packages/myst-cli/src/process/file.ts
+++ b/packages/myst-cli/src/process/file.ts
@@ -37,7 +37,7 @@ export async function loadFile(
 
   let location = file;
   if (projectPath) {
-    location = path.relative(projectPath, file);
+    location = `/${path.relative(projectPath, file)}`;
   }
   // ensure forward slashes and not windows backslashes
   location = location.replaceAll('\\', '/');