diff --git a/unittest/force-styles/tests/improper-sqdistharm.yaml b/unittest/force-styles/tests/improper-sqdistharm.yaml
index 8bf671efbd..74ff07bb9a 100644
--- a/unittest/force-styles/tests/improper-sqdistharm.yaml
+++ b/unittest/force-styles/tests/improper-sqdistharm.yaml
@@ -13,7 +13,9 @@ improper_style: sqdistharm
 improper_coeff: ! |
   1  75.0 5.5
   2  45.0 6.2
-extract: ! ""
+extract: ! |
+  k 1
+  chi 1
 natoms: 29
 init_energy: 3997.62616072489
 init_stress: ! |2-