diff --git a/.envrc b/.envrc
index 3550a30f2..f0b6459dc 100644
--- a/.envrc
+++ b/.envrc
@@ -1 +1,4 @@
-use flake
+source_up_if_exists
+if [ -z "${IN_NIX_SHELL:-}" ]; then
+  use flake .
+fi