diff --git a/windows/winctrls.c b/windows/winctrls.c
index d5b962ae..a03967e6 100644
--- a/windows/winctrls.c
+++ b/windows/winctrls.c
@@ -301,6 +301,7 @@ void bareradioline(struct ctlpos *cp, int nacross, ...)
 	if (!btext)
 	    break;
 	(void) va_arg(ap, int); /* id */
+        nbuttons++;
     }
     va_end(ap);
     buttons = snewn(nbuttons, struct radio);
@@ -331,6 +332,7 @@ void radiobig(struct ctlpos *cp, char *text, int id, ...)
 	if (!btext)
 	    break;
 	(void) va_arg(ap, int); /* id */
+        nbuttons++;
     }
     va_end(ap);
     buttons = snewn(nbuttons, struct radio);