diff --git a/fine-roaringbitmap/src/main/java/com/fr/third/bitmap/roaringbitmap/RoaringBitmap.java b/fine-roaringbitmap/src/main/java/com/fr/third/bitmap/roaringbitmap/RoaringBitmap.java
index 146848602..0c0dc875e 100644
--- a/fine-roaringbitmap/src/main/java/com/fr/third/bitmap/roaringbitmap/RoaringBitmap.java
+++ b/fine-roaringbitmap/src/main/java/com/fr/third/bitmap/roaringbitmap/RoaringBitmap.java
@@ -65,7 +65,7 @@ public class RoaringBitmap {
         int lenDiff = 0;
         if (sIdx1 > 0) {
             byte b = value[sIdx0 - 1];
-            byte b2 = (byte) (~(b & 0xff) >> sIdx1 << sIdx1 + ((b & 0xff) << (32 - sIdx1) >> (32 - sIdx1)));
+            byte b2 = (byte) (b ^ (0xff - (int) Math.pow(2, eIdx1) + 1));
             value[sIdx0 - 1] = b2;
             lenDiff += countInByte(b2) - countInByte(b);
         }
@@ -75,7 +75,7 @@ public class RoaringBitmap {
         }
         if (eIdx1 > 0) {
             byte b = value[eIdx0];
-            byte b2 = (byte) (((b & 0xff) >> eIdx1 << eIdx1) + ~(b & 0xff) << (32 - eIdx1) >> (32 - eIdx1));
+            byte b2 = (byte) (b ^ ((int) Math.pow(2, eIdx1) - 1));
             value[eIdx0] = b2;
             lenDiff += countInByte(b2) - countInByte(b);
         }