diff --git a/env.sh b/env.sh
index 578bef1d..d9259f34 100644
--- a/env.sh
+++ b/env.sh
@@ -16,7 +16,7 @@ hscloud_path="$hscloud_root/bazel-bin/tools:$hscloud_root/bazel-bin/cluster/tool
 unset -f hscloud_root
 unset -f hscloud_path
 
-if command -v clang &> /dev/null; then
+if command -v clang &> /dev/null && [ -z $HSCLOUD_NIX ]; then
     # if we have clang, use it
     # avoids weird PATH issues with linkers, eg https://github.com/bazelbuild/bazel/issues/18834
     export CC=clang
diff --git a/shell.nix b/shell.nix
index 10dd95c1..1ef93010 100644
--- a/shell.nix
+++ b/shell.nix
@@ -20,6 +20,7 @@ in with hscloud.pkgs; let
     export NIX_SSL_CERT_FILE="${cacert}/etc/ssl/certs/ca-bundle.crt"
     export SSL_CERT_FILE="${cacert}/etc/ssl/certs/ca-bundle.crt"
     export FONTCONFIG_FILE="${fontconfig}"
+    export HSCLOUD_NIX=yes
 
     source ${toString ./.}/env.sh