diff --git a/scripts/nix-profile-daemon.sh.in b/scripts/nix-profile-daemon.sh.in
index 6a7318912..f0e396da0 100644
--- a/scripts/nix-profile-daemon.sh.in
+++ b/scripts/nix-profile-daemon.sh.in
@@ -1,4 +1,5 @@
 # Only execute this file once per shell.
+# This file is tested by tests/installer/default.nix.
 if [ -n "${__ETC_PROFILE_NIX_SOURCED:-}" ]; then return; fi
 __ETC_PROFILE_NIX_SOURCED=1
 
diff --git a/scripts/nix-profile.sh.in b/scripts/nix-profile.sh.in
index 7fa0f4a7f..e868399b1 100644
--- a/scripts/nix-profile.sh.in
+++ b/scripts/nix-profile.sh.in
@@ -1,3 +1,4 @@
+# This file is tested by tests/installer/default.nix.
 if [ -n "$HOME" ] && [ -n "$USER" ]; then
 
     # Set up the per-user profile.