diff --git a/extra/ui/x11/x11.factor b/extra/ui/x11/x11.factor
index 87ed6d2852..c9b23e10e3 100644
--- a/extra/ui/x11/x11.factor
+++ b/extra/ui/x11/x11.factor
@@ -93,8 +93,12 @@ M: world button-up-event
     send-button-up ;
 
 : mouse-event>scroll-direction ( event -- pair )
-    #! Reminder for myself: 4 is up, 5 is down
-    XButtonEvent-button 5 = 1 -1 ? 0 swap 2array ;
+    XButtonEvent-button {
+        { 4 { 0 -1 } }
+        { 5 { 0 1 } }
+        { 6 { -1 0 } }
+        { 7 { 1 0 } }
+    } at ;
 
 M: world wheel-event
     >r dup mouse-event>scroll-direction swap mouse-event-loc r>
diff --git a/extra/x11/events/events.factor b/extra/x11/events/events.factor
index 05b3318f4f..f40392891c 100644
--- a/extra/x11/events/events.factor
+++ b/extra/x11/events/events.factor
@@ -42,7 +42,7 @@ GENERIC: client-event ( event window -- )
 
 : events-queued ( mode -- n ) >r dpy get r> XEventsQueued ;
 
-: wheel? ( event -- ? ) XButtonEvent-button { 4 5 } member? ;
+: wheel? ( event -- ? ) XButtonEvent-button 4 7 between? ;
 
 : button-down-event$ ( event window -- )
     over wheel? [ wheel-event ] [ button-down-event ] if ;