diff --git a/unittest/force-styles/tests/mol-pair-soft.yaml b/unittest/force-styles/tests/mol-pair-soft.yaml
index e5be18374a..d7cba08f72 100644
--- a/unittest/force-styles/tests/mol-pair-soft.yaml
+++ b/unittest/force-styles/tests/mol-pair-soft.yaml
@@ -1,6 +1,7 @@
 ---
 lammps_version: 10 Feb 2021
 date_generated: Fri Feb 26 23:08:56 2021
+tags: unstable
 epsilon: 1.5e-12
 prerequisites: ! |
   atom full