diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6109fac9..27cc543b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -83,6 +83,7 @@
 * Sixel “current geometry” query response not being bounded by the
   current window dimensions (fixes `lsix` output)
 * Crash on keyboard input when repeat rate was zero (i.e. no repeat).
+* Wrong button encoding of mouse buttons 6 and 7 in mouse events.
 
 
 ### Security
diff --git a/terminal.c b/terminal.c
index bb62195d..5344cc53 100644
--- a/terminal.c
+++ b/terminal.c
@@ -2369,14 +2369,10 @@ encode_xbutton(int xbutton)
     case 1: case 2: case 3:
         return xbutton - 1;
 
-    case 4: case 5:
+    case 4: case 5: case 6: case 7:
         /* Like button 1 and 2, but with 64 added */
         return xbutton - 4 + 64;
 
-    case 6: case 7:
-        /* Same as 4 and 5. Note: the offset should be something else? */
-        return xbutton - 6 + 64;
-
     case 8: case 9: case 10: case 11:
         /* Similar to 4 and 5, but adding 128 instead of 64 */
         return xbutton - 8 + 128;