diff --git a/tests/Fist/sample_pot/deca_ala.pot b/tests/Fist/sample_pot/deca_ala.pot
index 63d2f79d0b..f83cff0e1c 100644
--- a/tests/Fist/sample_pot/deca_ala.pot
+++ b/tests/Fist/sample_pot/deca_ala.pot
@@ -98,6 +98,11 @@ HA   CXX  NH1  H        0.0000  3     0.00
 
 
 IMPROPER
+C    CT3  O    NH1   120.0000         0      0.0000
+NH1  C    H    CT1    20.0000         0      0.0000
+C    CT1  O    NH1   120.0000         0      0.0000
+NH1  C    H    CXX    20.0000         0      0.0000
+
 
 NONBONDED
 CT3    0.000000  -0.080000     2.060000   0.000000  -0.010000     1.900000