diff --git a/src/Mod/Fem/femsolver/calculix/write_constraint_force.py b/src/Mod/Fem/femsolver/calculix/write_constraint_force.py
index a5a08b7945..785fbade16 100644
--- a/src/Mod/Fem/femsolver/calculix/write_constraint_force.py
+++ b/src/Mod/Fem/femsolver/calculix/write_constraint_force.py
@@ -56,13 +56,13 @@ def write_meshdata_constraint(f, femobj, force_obj, ccxwriter):
             node_load = ref_shape[1][n]
             # the loads in ref_shape[1][n] are without unit
             if abs(direction_vec.x) > dir_zero_tol:
-                v1 = "{}".format(direction_vec.x * node_load)
+                v1 = "{:.13G}".format((direction_vec.x * node_load).Value)
                 f.write("{},1,{}\n".format(n, v1))
             if abs(direction_vec.y) > dir_zero_tol:
-                v2 = "{}".format(direction_vec.y * node_load)
+                v2 = "{:.13G}".format((direction_vec.y * node_load).Value)
                 f.write("{},2,{}\n".format(n, v2))
             if abs(direction_vec.z) > dir_zero_tol:
-                v3 = "{}".format(direction_vec.z * node_load)
+                v3 = "{:.13G}".format((direction_vec.z * node_load).Value)
                 f.write("{},3,{}\n".format(n, v3))
         f.write("\n")
     f.write("\n")