diff --git a/kvmd/validators/kvm.py b/kvmd/validators/kvm.py
index b49123e1..3a1c437b 100644
--- a/kvmd/validators/kvm.py
+++ b/kvmd/validators/kvm.py
@@ -76,7 +76,7 @@ def valid_hid_mouse_move(arg: Any) -> int:
 
 
 def valid_hid_mouse_button(arg: Any) -> str:
-    return check_string_in_list(arg, "HID mouse button", ["left", "right"])
+    return check_string_in_list(arg, "HID mouse button", ["left", "right", "middle"])
 
 
 def valid_hid_mouse_wheel(arg: Any) -> int:
diff --git a/web/kvm/index.html b/web/kvm/index.html
index 71e92548..92df8097 100644
--- a/web/kvm/index.html
+++ b/web/kvm/index.html
@@ -304,6 +304,9 @@
 					<div data-code="left" class="key wide-4 left small"><p>Mouse<br>Left</p></div>
 					<div data-code="left" class="modifier wide-2 left small"><p><b>&bull;</b><br>&larr; Hold</p></div>
 					<div class="empty-key" style="width:10px"></div>
+					<div data-code="middle" class="key wide-2 left small"><p>Mouse<br>Middle</p></div>
+					<div data-code="middle" class="modifier wide-2 left small"><p><b>&bull;</b><br>&larr; Hold</p></div>
+					<div class="empty-key" style="width:10px"></div>
 					<div data-code="right" class="modifier wide-2 right small"><p><b>&bull;</b><br>Hold &rarr;</p></div>
 					<div data-code="right" class="key wide-4 right small"><p>Mouse<br>Right</p></div>
 				</div>
diff --git a/web/share/js/kvm/mouse.js b/web/share/js/kvm/mouse.js
index cf2dfac4..85efa199 100644
--- a/web/share/js/kvm/mouse.js
+++ b/web/share/js/kvm/mouse.js
@@ -121,6 +121,7 @@ export function Mouse() {
 		switch (event.button) {
 			case 0: __keypad.emit("left", state); break;
 			case 2: __keypad.emit("right", state); break;
+			case 1: __keypad.emit("middle", state); break;
 		}
 	};