diff --git a/windows/spinbox.cpp b/windows/spinbox.cpp
index 2b6af66d..8c4b666a 100644
--- a/windows/spinbox.cpp
+++ b/windows/spinbox.cpp
@@ -32,6 +32,7 @@ static int value(uiSpinbox *s)
 
 // control implementation
 
+// TODO assign lResult
 static BOOL onWM_COMMAND(uiControl *c, HWND hwnd, WORD code, LRESULT *lResult)
 {
 	uiSpinbox *s = (uiSpinbox *) c;