diff --git a/src/mathematics/mathematics_functions.h b/src/mathematics/mathematics_functions.h
index 5557d0e3..9c95cbf8 100644
--- a/src/mathematics/mathematics_functions.h
+++ b/src/mathematics/mathematics_functions.h
@@ -37,7 +37,7 @@ namespace reactphysics3d {
 
 // function to test if two real numbers are (almost) equal
 // We test if two numbers a and b are such that (a-b) are in [-EPSILON; EPSILON]
-inline bool approxEqual(decimal a, decimal b, decimal epsilon = 1.0e-10) {
+inline bool approxEqual(decimal a, decimal b, decimal epsilon = MACHINE_EPSILON) {
     decimal difference = a - b;
     return (difference < epsilon && difference > -epsilon);
 }