diff --git a/flake.nix b/flake.nix
index a0f8d00..f1e75b3 100644
--- a/flake.nix
+++ b/flake.nix
@@ -43,6 +43,7 @@
           rust-toolchain
           pkgs.cargo-release
           pkgs.cargo-expand
+          pkgs.foundry-bin
           pkgs.gmp
           pkgs.openssl
           pkgs.libusb1
@@ -343,6 +344,7 @@
           body = ''
             bats test/bats/devshell/rust-shell/closure.test.bats
             bats test/bats/devshell/rust-shell/cargo-expand.test.bats
+            bats test/bats/devshell/rust-shell/anvil.test.bats
           '';
           additionalBuildInputs = [ pkgs.bats ] ++ rust-build-inputs;
         };
diff --git a/test/bats/devshell/rust-shell/anvil.test.bats b/test/bats/devshell/rust-shell/anvil.test.bats
new file mode 100644
index 0000000..bec9653
--- /dev/null
+++ b/test/bats/devshell/rust-shell/anvil.test.bats
@@ -0,0 +1,4 @@
+@test "anvil should be available on PATH" {
+  run anvil --version
+  [ "$status" -eq 0 ]
+}
diff --git a/test/bats/devshell/rust-shell/closure.test.bats b/test/bats/devshell/rust-shell/closure.test.bats
index 3537bfb..1b3602f 100644
--- a/test/bats/devshell/rust-shell/closure.test.bats
+++ b/test/bats/devshell/rust-shell/closure.test.bats
@@ -7,10 +7,10 @@
 # time CI evaluates the shell.
 #
 # This file inspects rust-shell's full closure (`nix-store -q
-# --requisites`) and fails if any sol toolchain, node/npm, or chromium
-# component shows up. rust-shell is for repos that ship a pure rust
-# binary (rain.cli, rain.metadoc, etc.) and should not pull in foundry,
-# slither, solc, nodejs, or chromium.
+# --requisites`) and fails if slither, solc, node/npm, or chromium
+# show up. rust-shell ships foundry-bin so that alloy's Anvil::new()
+# spawn works in cargo tests, but does not pull in the rest of the
+# Solidity static-analysis toolchain.
 #
 # Skips when `nix` is not on PATH (e.g. running the bats files under a
 # stripped sandbox); CI invokes via nix and so always exercises this.
@@ -28,11 +28,11 @@ setup() {
   CLOSURE="$(nix-store -q --requisites "$RUST_SHELL_OUT")"
 }
 
-@test "rust-shell closure has no foundry toolchain" {
+@test "rust-shell closure has no slither or solc" {
   local hits
-  hits="$(echo "$CLOSURE" | grep -E '/nix/store/[^/]*-(foundry-|solc-static-|slither-analyzer-)' || true)"
+  hits="$(echo "$CLOSURE" | grep -E '/nix/store/[^/]*-(solc-static-|slither-analyzer-)' || true)"
   if [ -n "$hits" ]; then
-    echo "FAIL: rust-shell closure references sol toolchain components:" >&2
+    echo "FAIL: rust-shell closure references sol static-analysis components:" >&2
     echo "$hits" >&2
     return 1
   fi