diff --git a/backend/backend.cabal b/backend/backend.cabal
index 25f6903..5c5d763 100644
--- a/backend/backend.cabal
+++ b/backend/backend.cabal
@@ -12,6 +12,7 @@ library
                , frontend
                , obelisk-backend
                , obelisk-route
+               , tahoe-chk
   exposed-modules:
     Backend
   ghc-options: -Wall -Wredundant-constraints -Wincomplete-uni-patterns -Wincomplete-record-updates -O -fno-show-valid-hole-fits
diff --git a/default.nix b/default.nix
index b12eabc..7f0a11a 100644
--- a/default.nix
+++ b/default.nix
@@ -37,8 +37,8 @@ project ./. ({ pkgs, hackGet, ... }: {
       # We also ended up needing an override of the base32 library, which we obtain from Hackage.
       base32 = self.callHackageDirect {
         pkg = "base32";
-        ver = "0.2.2.0";
-        sha256 = "1qx7n2jyb9h1082434r90hfrjw5fab2j1yg0qzxh856fpksbh811";
-      };
+        ver = "0.2.1.0";
+        sha256 = "04glpmwp50qi29h8cb5j0w1rz0ww30nw4xgj2a3l7zh1gprhwj89";
+      } {};
     };
 })