diff --git a/st.c b/st.c
index 623376e..3d250dd 100644
--- a/st.c
+++ b/st.c
@@ -1097,7 +1097,7 @@ tscrollup(int orig, int n)
 void
 selscroll(int orig, int n)
 {
-	if (sel.ob.x == -1)
+	if (sel.ob.x == -1 || sel.alt != IS_SET(MODE_ALTSCREEN))
 		return;
 
 	if (BETWEEN(sel.nb.y, orig, term.bot) != BETWEEN(sel.ne.y, orig, term.bot)) {