diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..9b42106
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+.direnv/
diff --git a/direnvrc b/direnvrc
index fc7849a..527c0dc 100644
--- a/direnvrc
+++ b/direnvrc
@@ -60,6 +60,10 @@ use_nix() {
     unset TMPDIR
   fi
 
+  # `nix-shell --pure` sets IN_NIX_SHELL to pure which is
+  # misleading since we are in an impure shell now
+  export IN_NIX_SHELL=impure
+
   # `nix-shell --pure` sets invalid ssl certificate paths
   if [[ "${SSL_CERT_FILE:-}" = /no-cert-file.crt ]]; then
     if [[ ${impure_ssl_cert_file} == __UNSET__ ]]; then