diff --git a/libs/phys/source/engine_2d.cpp b/libs/phys/source/engine_2d.cpp
index 7c7fabba..10dbe2b8 100644
--- a/libs/phys/source/engine_2d.cpp
+++ b/libs/phys/source/engine_2d.cpp
@@ -473,7 +473,7 @@ namespace psemek::phys2d
 						float q = geom::length(J - n * geom::dot(J, n));
 						if (q > mu * geom::dot(J, n))
 						{
-							float k = (mu * (1.f + e) * geom::dot(J1, n)) / (q - mu * geom::dot(n, J2 - J1));
+							float k = (mu * (1.f + e) * geom::dot(J1, n)) / (geom::length(J2 - n * geom::dot(J2, n)) - mu * geom::dot(n, J2 - J1));
 							J = (1.f + e) * J1 + k * (J2 - J1);
 						}