diff --git a/scripts/update-flake.sh b/scripts/update-flake.sh
index 4094f20032611..67aca5e79a09a 100755
--- a/scripts/update-flake.sh
+++ b/scripts/update-flake.sh
@@ -13,4 +13,4 @@ echo "Calculating SRI hash..."
 HASH=$(go run tailscale.com/cmd/nardump --sri "$OUT/pkg/mod/cache/download")
 sudo rm -rf "$OUT"
 
-sed -i "s/\(vendorHash = \"\)[^\"]*/\1${HASH}/" ./flake.nix
+sed -i "s#\(vendorHash = \"\)[^\"]*#\1${HASH}#" ./flake.nix