diff --git a/Tests/Framework/BoundingTest.cs b/Tests/Framework/BoundingTest.cs
index 7ab99d15f9e..c1112c99fd3 100644
--- a/Tests/Framework/BoundingTest.cs
+++ b/Tests/Framework/BoundingTest.cs
@@ -290,12 +290,14 @@ public void BoundingFrustumIntersectsBoundingSphere()
             var bsphere3 = new BoundingSphere(-Vector3.One * 6, 1);
             var bsphere4 = new BoundingSphere(Vector3.Zero, 200);
             var bsphere5 = new BoundingSphere(new Vector3(1, 1, 5), 1);
+            var bsphere6 = new BoundingSphere(new Vector3(0, 0, -95), 1);
 
             Assert.AreEqual(testFrustum.Intersects(bsphere1), true);
             Assert.AreEqual(testFrustum.Intersects(bsphere2), true);
             Assert.AreEqual(testFrustum.Intersects(bsphere3), false);
             Assert.AreEqual(testFrustum.Intersects(bsphere4), true);
             Assert.AreEqual(testFrustum.Intersects(bsphere5), false);
+            Assert.AreEqual(testFrustum.Intersects(bsphere6), true);
         }
 
         [Test]
@@ -310,6 +312,7 @@ public void BoundingFrustumContainsBoundingSphere()
             var bsphere3 = new BoundingSphere(-Vector3.One * 6, 1);
             var bsphere4 = new BoundingSphere(Vector3.Zero, 200);
             var bsphere5 = new BoundingSphere(new Vector3(1, 1, 5), 1);
+            var bsphere6 = new BoundingSphere(new Vector3(0, 0, -95), 1);
 
             Assert.AreEqual(testFrustum.Contains(bsphere1), ContainmentType.Contains);
             Assert.AreEqual(testFrustum.Contains(bsphere2), ContainmentType.Contains);
@@ -318,6 +321,7 @@ public void BoundingFrustumContainsBoundingSphere()
 #if !XNA    // XNA reports a false Intersects
             Assert.AreEqual(testFrustum.Contains(bsphere5), ContainmentType.Disjoint);
 #endif
+            Assert.AreEqual(testFrustum.Contains(bsphere6), ContainmentType.Intersects);
         }
 
         [Test]
diff --git a/src/Xna.Framework/IntersectsHelper.cs b/src/Xna.Framework/IntersectsHelper.cs
index d0b2d797b45..78ca2298906 100644
--- a/src/Xna.Framework/IntersectsHelper.cs
+++ b/src/Xna.Framework/IntersectsHelper.cs
@@ -281,7 +281,7 @@ internal static void BoundingFrustumIntersectsBoundingSphere(BoundingFrustum fru
                 }
             }
 
-            if (back == BoundingFrustum.PlaneCount)
+            if (back >= (BoundingFrustum.PlaneCount - 1))
                 return;
 
             if (SegmentIntersectsBoundingSphere(ref frustum._corners[0], ref frustum._corners[1], ref sphere))