diff --git a/ProcessLib/HydroMechanics/Tests.cmake b/ProcessLib/HydroMechanics/Tests.cmake
index 337055ee555e1b0181ed3ed39a68d3278b5a83d7..9f03c56dbef2ba3564fc562331d89b77e759920d 100644
--- a/ProcessLib/HydroMechanics/Tests.cmake
+++ b/ProcessLib/HydroMechanics/Tests.cmake
@@ -347,7 +347,7 @@ AddTest(
     DIFF_DATA
     # tolerance could be lowered with smaller time steps, gut would increase runtime
     # TODO (FZill) another solver might provide better results, same goes for "flow_free_expansion"
-    flow_no_strain_ts_1000_t_100.000000.vtu flow_no_strain_ts_1000_t_100.000000.vtu pressure pressure 0 1.5e-6
+    flow_no_strain_ts_1000_t_100.000000.vtu flow_no_strain_ts_1000_t_100.000000.vtu pressure pressure 0 1.6e-6
     flow_no_strain_ts_1000_t_100.000000.vtu flow_no_strain_ts_1000_t_100.000000.vtu displacement displacement 1e-12 0
 )