diff --git a/src/screen.c b/src/screen.c
index 3713f49..7caf299 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -3707,7 +3707,15 @@
      */
     result_empty = (row + line_count >= end);
     if (wp != NULL && wp->w_width != Columns && *T_CSV == NUL)
+    {
+	// Avoid that lines are first cleared here and then redrawn, which
+	// results in many characters updated twice.  This happens with CTRL-F
+	// in a vertically split window.  With line-by-line scrolling
+	// USE_REDRAW should be faster.
+	if (line_count > 3)
+	    return FAIL;
 	type = USE_REDRAW;
+    }
     else if (can_clear(T_CD) && result_empty)
 	type = USE_T_CD;
     else if (*T_CAL != NUL && (line_count > 1 || *T_AL == NUL))
@@ -3879,7 +3887,7 @@
     int		end,
     int		force,		// even when line_count > p_ttyscroll
     int		clear_attr,	// used for clearing lines
-    win_T	*wp UNUSED)	// NULL or window to use width from
+    win_T	*wp)		// NULL or window to use width from
 {
     int		j;
     int		i;
@@ -3934,7 +3942,15 @@
      * 6. redraw the characters from ScreenLines[].
      */
     if (wp != NULL && wp->w_width != Columns && *T_CSV == NUL)
+    {
+	// Avoid that lines are first cleared here and then redrawn, which
+	// results in many characters updated twice.  This happens with CTRL-F
+	// in a vertically split window.  With line-by-line scrolling
+	// USE_REDRAW should be faster.
+	if (line_count > 3)
+	    return FAIL;
 	type = USE_REDRAW;
+    }
     else if (can_clear(T_CD) && result_empty)
 	type = USE_T_CD;
     else if (row == 0 && (