diff --git a/src/move.c b/src/move.c
index 32cd6f3..343c6c8 100644
--- a/src/move.c
+++ b/src/move.c
@@ -552,6 +552,16 @@
 				      |VALID_BOTLINE|VALID_BOTLINE_AP);
 	wp->w_valid_cursor = wp->w_cursor;
 	wp->w_valid_leftcol = wp->w_leftcol;
+	wp->w_valid_skipcol = wp->w_skipcol;
+    }
+    else if (wp->w_skipcol != wp->w_valid_skipcol)
+    {
+	wp->w_valid &= ~(VALID_WROW|VALID_WCOL|VALID_VIRTCOL
+				      |VALID_CHEIGHT|VALID_CROW
+				      |VALID_BOTLINE|VALID_BOTLINE_AP);
+	wp->w_valid_cursor = wp->w_cursor;
+	wp->w_valid_leftcol = wp->w_leftcol;
+	wp->w_valid_skipcol = wp->w_skipcol;
     }
     else if (wp->w_cursor.col != wp->w_valid_cursor.col
 	     || wp->w_leftcol != wp->w_valid_leftcol
@@ -878,7 +888,6 @@
 
     redraw_for_cursorline(curwin);
     wp->w_valid |= VALID_CROW|VALID_CHEIGHT;
-
 }
 
 /*
@@ -1092,6 +1101,11 @@
     {
 	width = textwidth + curwin_col_off2();
 
+	// skip columns that are not visible
+	if (curwin->w_cursor.lnum == curwin->w_topline
+		&& curwin->w_wcol >= curwin->w_skipcol)
+	    curwin->w_wcol -= curwin->w_skipcol;
+
 	// long line wrapping, adjust curwin->w_wrow
 	if (curwin->w_wcol >= curwin->w_width)
 	{
@@ -1265,10 +1279,12 @@
 	    while (endcol > curwin->w_virtcol)
 		endcol -= width;
 	    if (endcol > curwin->w_skipcol)
+	    {
+		curwin->w_wrow -= (endcol - curwin->w_skipcol) / width;
 		curwin->w_skipcol = endcol;
+	    }
 	}
 
-	curwin->w_wrow -= curwin->w_skipcol / width;
 	if (curwin->w_wrow >= curwin->w_height)
 	{
 	    // small window, make sure cursor is in it
@@ -1302,8 +1318,10 @@
 	curwin->w_flags &= ~(WFLAG_WCOL_OFF_ADDED + WFLAG_WROW_OFF_ADDED);
 #endif
 
-    // now w_leftcol is valid, avoid check_cursor_moved() thinking otherwise
+    // now w_leftcol and w_skipcol are valid, avoid check_cursor_moved()
+    // thinking otherwise
     curwin->w_valid_leftcol = curwin->w_leftcol;
+    curwin->w_valid_skipcol = curwin->w_skipcol;
 
     curwin->w_valid |= VALID_WCOL|VALID_WROW|VALID_VIRTCOL;
 }
@@ -1772,10 +1790,74 @@
 		col += width2;
 	    curwin->w_curswant = col;
 	    coladvance(curwin->w_curswant);
+
+	    // validate_virtcol() marked various things as valid, but after
+	    // moving the cursor they need to be recomputed
+	    curwin->w_valid &=
+	       ~(VALID_WROW|VALID_WCOL|VALID_CHEIGHT|VALID_CROW|VALID_VIRTCOL);
 	}
     }
 }
 
+/*
+ * Called after changing the cursor column: make sure that curwin->w_skipcol is
+ * valid for 'smoothscroll'.
+ */
+    void
+adjust_skipcol(void)
+{
+    if (!curwin->w_p_wrap
+	    || !curwin->w_p_sms
+	    || curwin->w_cursor.lnum != curwin->w_topline)
+	return;
+
+    int	    width1 = curwin->w_width - curwin_col_off();
+    int	    width2 = width1 + curwin_col_off2();
+    long    so = curwin->w_p_so >= 0 ? curwin->w_p_so : p_so;
+    int	    scrolloff_cols = so == 0 ? 0 : width1 + (so - 1) * width2;
+    int	    scrolled = FALSE;
+
+    validate_virtcol();
+    while (curwin->w_skipcol > 0
+		 && curwin->w_virtcol < curwin->w_skipcol + 3 + scrolloff_cols)
+    {
+	// scroll a screen line down
+	if (curwin->w_skipcol >= width1 + width2)
+	    curwin->w_skipcol -= width2;
+	else
+	    curwin->w_skipcol -= width1;
+	redraw_later(UPD_NOT_VALID);
+	scrolled = TRUE;
+	validate_virtcol();
+    }
+    if (scrolled)
+	return;  // don't scroll in the other direction now
+
+    int col = curwin->w_virtcol - curwin->w_skipcol + scrolloff_cols;
+    int row = 0;
+    if (col >= width1)
+    {
+	col -= width1;
+	++row;
+    }
+    if (col > width2)
+    {
+	row += col / width2;
+	col = col % width2;
+    }
+    if (row >= curwin->w_height)
+    {
+	if (curwin->w_skipcol == 0)
+	{
+	    curwin->w_skipcol += width1;
+	    --row;
+	}
+	if (row >= curwin->w_height)
+	    curwin->w_skipcol += (row - curwin->w_height) * width2;
+	redraw_later(UPD_NOT_VALID);
+    }
+}
+
 #ifdef FEAT_DIFF
 /*
  * Don't end up with too many filler lines in the window.