diff -r 1c8e6796c6fe st.c
--- a/st.c	Sun Aug 14 17:15:19 2011 +0200
+++ b/st.c	Wed Sep 14 15:38:20 2011 +0200
@@ -231,6 +231,7 @@
 static inline int selected(int, int);
 static void selcopy(void);
 static void selpaste();
+static void scrollsel(int, int);
 
 static int utf8decode(char *, long *);
 static int utf8encode(long *, char *);
@@ -801,6 +802,8 @@
 		term.line[i] = term.line[i-n];
 		term.line[i-n] = temp;
 	}
+
+	scrollsel(orig, n);
 }
 
 void
@@ -816,6 +819,29 @@
 		 term.line[i] = term.line[i+n];
 		 term.line[i+n] = temp;
 	}
+
+	scrollsel(orig, -n);
+}
+
+void
+scrollsel(int orig, int n) {
+	if(sel.bx == -1) return;
+	if(BETWEEN(sel.by, orig, term.bot) || BETWEEN(sel.ey, orig, term.bot)) {
+		if((sel.by+=n) > term.bot || (sel.ey+=n) < term.top) {
+			sel.bx=-1;
+			return;
+		}
+		if(sel.by<term.top) {
+			sel.by=term.top;
+			sel.bx=0;
+		}
+		if(sel.ey>term.bot) {
+			sel.ey=term.bot;
+			sel.ex=term.col;
+		}
+		sel.b.y=sel.by; sel.b.x=sel.bx;
+		sel.e.y=sel.ey; sel.e.x=sel.ex;
+	}
 }
 
 void
@@ -1072,6 +1098,7 @@
 		break;
 	/* XXX: (CSI n I) CHT -- Cursor Forward Tabulation <n> tab stops */
 	case 'J': /* ED -- Clear screen */
+		sel.bx = -1;
 		switch(escseq.arg[0]) {
 		case 0: /* below */
 			tclearregion(term.c.x, term.c.y, term.col-1, term.c.y);
@@ -1377,6 +1404,7 @@
 			}
 		}
 	} else {
+		if(sel.bx != -1 && BETWEEN(term.c.y, sel.by, sel.ey)) sel.bx = -1;
 		switch(ascii) {
 		case '\t':
 			tputtab();