diff --git a/.envrc b/.envrc
index 24e67d2ee..7ee2b88b4 100644
--- a/.envrc
+++ b/.envrc
@@ -1,5 +1,5 @@
 # If we are a computer with nix-shell available, then use that to setup
 # the build environment with exactly what we need.
 if has nix; then
-  use nix
+  use flake
 fi
diff --git a/nix/devshell.nix b/nix/devshell.nix
index 3326f83d6..343546312 100644
--- a/nix/devshell.nix
+++ b/nix/devshell.nix
@@ -73,13 +73,14 @@ in mkShell rec {
     parallel
     python
     tracy
-    valgrind
     vttest
-    wraptest
 
     # wasm
     wabt
     wasmtime
+  ] ++ lib.optionals stdenv.isLinux [
+    valgrind
+    wraptest
   ];
 
   buildInputs = [