diff --git a/diigo-cache/scripts/compare-export.ts b/diigo-cache/scripts/compare-export.ts
index 533e47a..96b7979 100644
--- a/diigo-cache/scripts/compare-export.ts
+++ b/diigo-cache/scripts/compare-export.ts
@@ -154,4 +154,5 @@ export function main(
 	exit(0);
 }
 
-main();
+// run only as a program, not when imported (e.g. by a test)
+if (import.meta.main) main();