diff --git a/pymoo/operators/crossover/sbx.py b/pymoo/operators/crossover/sbx.py
index d2f3a309..1150246f 100644
--- a/pymoo/operators/crossover/sbx.py
+++ b/pymoo/operators/crossover/sbx.py
@@ -70,7 +70,10 @@ def calc_betaq(beta):
     child2 = np.where(sm, c2, c1)  # child for parent 2
     
     # exchange children with given probability
-    b = np.random.random(len(prob_bin)) < prob_bin
+    b = np.bitwise_xor(
+        np.random.random(len(prob_bin)) < prob_bin,
+        X[0, cross] > X[1, cross]
+    )
     child1, child2 = np.where(b, (child2, child1), (child1, child2))
 
     # first copy the unmodified parents