diff --git a/compare-hashes.ps1 b/compare-hashes.ps1
new file mode 100644
index 0000000..0b3cef0
--- /dev/null
+++ b/compare-hashes.ps1
@@ -0,0 +1,4 @@
+# on linux: md5sum bson.sql.tar.gz > bson.tar.gz.md5
+# on windows: FCIV -md5 bson.tar.gz > bson.tar.gz.md5
+# https://support.microsoft.com/en-us/topic/d92a713f-d793-7bd8-b0a4-4db811e29559
+diff (echo (FCIV -md5 bson.tar.gz)|Select -Last 1) (cat bson.tar.gz.md5)