diff --git a/unittest/force-styles/tests/angle-quartic.yaml b/unittest/force-styles/tests/angle-quartic.yaml
index 6ded709e84..15ec06d82a 100644
--- a/unittest/force-styles/tests/angle-quartic.yaml
+++ b/unittest/force-styles/tests/angle-quartic.yaml
@@ -16,7 +16,11 @@ angle_coeff: ! |
   3 120.0  50.0  -9.5 -1.5
   4 108.5 100.0   5.0 -2.0
 equilibrium: 4 1.9216075064457565 1.9373154697137058 2.0943951023931953 1.8936822384138474
-extract: ! ""
+extract: ! |
+  k2 1
+  k3 1
+  k4 1
+  theta0 1
 natoms: 29
 init_energy: 41.0458477552901
 init_stress: ! |2-