diff --git a/tools/depotfmt.nix b/tools/depotfmt.nix
index 2d70c3f2b..21e71bf3b 100644
--- a/tools/depotfmt.nix
+++ b/tools/depotfmt.nix
@@ -38,6 +38,7 @@ let
   # wrapper script for running formatting checks in CI
   check = pkgs.writeShellScript "depotfmt-check" ''
     ${pkgs.treefmt}/bin/treefmt \
+      --clear-cache \
       --fail-on-change \
       --config-file ${config} \
       --tree-root .