diff --git a/nixos/tests/osquery.nix b/nixos/tests/osquery.nix
index 9aa9820e50c5..e98e7c1baf04 100644
--- a/nixos/tests/osquery.nix
+++ b/nixos/tests/osquery.nix
@@ -36,7 +36,7 @@ in
       machine.succeed("echo 'SELECT address FROM etc_hosts LIMIT 1;' | osqueryi | tee /dev/console | grep -q '127.0.0.1'")
 
       # osquery binaries respect configuration from the Nix config option.
-      machine.succeed("echo 'SELECT value FROM osquery_flags WHERE name = \"utc\";' | osqueryi | tee /dev/console | grep -q ${boolToString utc}")
+      machine.succeed("echo 'SELECT value FROM osquery_flags WHERE name = \"utc\";' | osqueryi | tee /dev/console | grep -q ${lib.boolToString utc}")
 
       # osquery binaries respect configuration from the Nix flags option.
       machine.succeed("echo 'SELECT value FROM osquery_flags WHERE name = \"config_refresh\";' | osqueryi | tee /dev/console | grep -q ${config_refresh}")