diff --git a/.envrc b/.envrc
index 6cc94f514..24e67d2ee 100644
--- a/.envrc
+++ b/.envrc
@@ -1,6 +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
-  # Can add ". --impure" if we ever need the parent shell environment. We might.
-  use flake
+  use nix
 fi