diff --git a/flake.nix b/flake.nix
index 8856430..4a5cb2b 100644
--- a/flake.nix
+++ b/flake.nix
@@ -141,12 +141,14 @@
           inherit cargoArtifacts;
           cargoExtraArgs = "--workspace --lib --test harness --test p1 --test durable --test 'cred*' --test layers --test regressions --test streams --test wasi";
           preCheck = ''
+            export SAUSAGE_CACHE="$TMPDIR/sausage-cache"
             mkdir -p target/userland
             ln -s ${userland} target/userland/bundle
           '';
           doInstallCargoArtifacts = false;
         });
         checks.shell = pkgs.runCommand "sausage-shell" { } ''
+          export SAUSAGE_CACHE="$TMPDIR/sausage-cache"
           ${sausage}/bin/sausage sh "$TMPDIR/world" -c \
             'ls /bin | wc -l; echo hi | tr a-z A-Z; git --version; rg --version' > output
           cat output