diff --git a/xpra/platform/win32/constants.py b/xpra/platform/win32/constants.py
index 98eb4247a7..c297e31ff6 100644
--- a/xpra/platform/win32/constants.py
+++ b/xpra/platform/win32/constants.py
@@ -2519,6 +2519,7 @@
 MONITOR_DEFAULTTONULL=0
 MONITOR_DEFAULTTOPRIMARY=1
 MOUSEEVENTF_ABSOLUTE=32768
+MOUSEEVENTF_HWHEEL=4096
 MOUSEEVENTF_LEFTDOWN=2
 MOUSEEVENTF_LEFTUP=4
 MOUSEEVENTF_MIDDLEDOWN=32
@@ -4712,6 +4713,8 @@
 WVR_REDRAW=768
 WVR_VALIDRECTS=1024
 WVR_VREDRAW=512
+XBUTTON1=1
+XBUTTON2=2
 cchTextLimitDefault=32767
 lDefaultTab=720
 yHeightCharPtsMost=1638
diff --git a/xpra/platform/win32/shadow_server.py b/xpra/platform/win32/shadow_server.py
index 221a6fd994..8174ca1b64 100644
--- a/xpra/platform/win32/shadow_server.py
+++ b/xpra/platform/win32/shadow_server.py
@@ -56,6 +56,14 @@
                  (4, False) : NOEVENT,
                  (5, True)  : (win32con.MOUSEEVENTF_WHEEL,      -win32con.WHEEL_DELTA),
                  (5, False) : NOEVENT,
+                 (6, True)  : (win32con.MOUSEEVENTF_HWHEEL,     win32con.WHEEL_DELTA),
+                 (6, False) : NOEVENT,
+                 (7, True)  : (win32con.MOUSEEVENTF_HWHEEL,     -win32con.WHEEL_DELTA),
+                 (7, False) : NOEVENT,
+                 (8, True)  : (win32con.MOUSEEVENTF_XDOWN,      win32con.XBUTTON1),
+                 (8, False) : (win32con.MOUSEEVENTF_XUP,        win32con.XBUTTON1),
+                 (9, True)  : (win32con.MOUSEEVENTF_XDOWN,      win32con.XBUTTON2),
+                 (9, False) : (win32con.MOUSEEVENTF_XUP,        win32con.XBUTTON2),
                  }
 
 SEAMLESS = envbool("XPRA_WIN32_SEAMLESS", False)