diff --git a/CHANGELOG.md b/CHANGELOG.md
index 960789c..85ccb87 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,17 @@ Change Log
 ==========
 
 
+## Unreleased
+
+**Fixed**
+
+- Mouse mode only responded to left click. The button codes were
+  hardcoded integers from `NCURSES_MOUSE_VERSION` 1, which gave each
+  button six bits; version 2 packs them into five to make room for
+  button 5, moving every value except `BUTTON1_RELEASED`. Right click
+  and both scroll directions were therefore matched against numbers
+  ncurses never sends. The codes now come from curses itself.
+
 ## [v0.3.2](https://github.com/leancode/suplemon/tree/0.3.2) (2026-09-03)
 
 Nothing here changes the installed package. The launcher fix affects the
diff --git a/suplemon/main.py b/suplemon/main.py
index 2a2461c..55ad113 100644
--- a/suplemon/main.py
+++ b/suplemon/main.py
@@ -6,6 +6,7 @@
 
 
 import os
+import curses
 import sys
 
 from . import ui
@@ -21,6 +22,12 @@
 __version__ = "0.3.2"
 
 
+# ncurses only defines BUTTON5 when built with NCURSES_MOUSE_VERSION 2.
+# Without it there is no wheel-down event to match, so scrolling down is
+# simply unavailable rather than mismatched.
+BUTTON5_PRESSED = getattr(curses, "BUTTON5_PRESSED", 0)
+
+
 class App:
     def __init__(self, filenames=None, config_file=None, log_level=None):
         """
@@ -340,13 +347,18 @@ def handle_mouse(self, event):
         :rtype: boolean
         """
         editor = self.get_editor()
-        if event.mouse_code == 1:                    # Left mouse button release
+        code = event.mouse_code
+        # These were hardcoded integers matching NCURSES_MOUSE_VERSION 1,
+        # which gave each button six bits. Version 2 packs them into five to
+        # make room for button 5, so every value except BUTTON1_RELEASED
+        # moved and only left click still worked. Ask curses instead.
+        if code & curses.BUTTON1_RELEASED:
             editor.set_single_cursor(event.mouse_pos)
-        elif event.mouse_code == 4096:               # Right mouse button release
+        elif code & curses.BUTTON3_RELEASED:
             editor.add_cursor(event.mouse_pos)
-        elif event.mouse_code == 524288:             # Wheel up
+        elif code & curses.BUTTON4_PRESSED:          # Wheel up
             editor.jump_up()
-        elif event.mouse_code == 134217728:          # Wheel down(and unfortunately left button drag)
+        elif BUTTON5_PRESSED and code & BUTTON5_PRESSED:
             editor.jump_down()
         else:
             return False