diff --git a/src/ops.c b/src/ops.c
index b5b064b..1d5d3bf 100644
--- a/src/ops.c
+++ b/src/ops.c
@@ -2184,6 +2184,8 @@
 }
 #endif
 
+static int swapchars __ARGS((int op_type, pos_T *pos, int length));
+
 /*
  * Handle the (non-standard vi) tilde operator.  Also for "gu", "gU" and "g?".
  */
@@ -2194,9 +2196,8 @@
     pos_T		pos;
 #ifdef FEAT_VISUAL
     struct block_def	bd;
-    int			todo;
 #endif
-    int			did_change = 0;
+    int			did_change;
 
     if (u_save((linenr_T)(oap->start.lnum - 1),
 				       (linenr_T)(oap->end.lnum + 1)) == FAIL)
@@ -2210,16 +2211,8 @@
 	{
 	    block_prep(oap, &bd, pos.lnum, FALSE);
 	    pos.col = bd.textcol;
-	    for (todo = bd.textlen; todo > 0; --todo)
-	    {
-# ifdef FEAT_MBYTE
-		if (has_mbyte)
-		    todo -= (*mb_ptr2len)(ml_get_pos(&pos)) - 1;
-# endif
-		did_change |= swapchar(oap->op_type, &pos);
-		if (inc(&pos) == -1)	    /* at end of file */
-		    break;
-	    }
+	    did_change = swapchars(oap->op_type, &pos, bd.textlen);
+
 # ifdef FEAT_NETBEANS_INTG
 	    if (usingNetbeans && did_change)
 	    {
@@ -2249,13 +2242,7 @@
 	else if (!oap->inclusive)
 	    dec(&(oap->end));
 
-	while (ltoreq(pos, oap->end))
-	{
-	    did_change |= swapchar(oap->op_type, &pos);
-	    if (inc(&pos) == -1)    /* at end of file */
-		break;
-	}
-
+	did_change = swapchars(oap->op_type, &pos, oap->end.col - pos.col + 1);
 	if (did_change)
 	{
 	    changed_lines(oap->start.lnum, oap->start.col, oap->end.lnum + 1,
@@ -2309,6 +2296,42 @@
 }
 
 /*
+ * Invoke swapchar() on "length" bytes at position "pos".
+ * "pos" is advanced to just after the changed characters.
+ * "length" is rounded up to include the whole last multi-byte character.
+ * Also works correctly when the number of bytes changes.
+ * Returns TRUE if some character was changed.
+ */
+    static int
+swapchars(op_type, pos, length)
+    int		op_type;
+    pos_T	*pos;
+    int		length;
+{
+    int todo;
+    int	did_change = 0;
+
+    for (todo = length; todo > 0; --todo)
+    {
+# ifdef FEAT_MBYTE
+	int pos_col = pos->col;
+
+	if (has_mbyte)
+	    /* we're counting bytes, not characters */
+	    todo -= (*mb_ptr2len)(ml_get_pos(pos)) - 1;
+# endif
+	did_change |= swapchar(op_type, pos);
+# ifdef FEAT_MBYTE
+	/* Changing German sharp s to SS increases the column. */
+	todo += pos->col - pos_col;
+# endif
+	if (inc(pos) == -1)    /* at end of file */
+	    break;
+    }
+    return did_change;
+}
+
+/*
  * If op_type == OP_UPPER: make uppercase,
  * if op_type == OP_LOWER: make lowercase,
  * if op_type == OP_ROT13: do rot13 encoding,
@@ -2330,7 +2353,8 @@
 	return FALSE;
 
 #ifdef FEAT_MBYTE
-    if (op_type == OP_UPPER && enc_latin1like && c == 0xdf)
+    if (op_type == OP_UPPER && c == 0xdf
+		      && (enc_latin1like || STRCMP(p_enc, "iso-8859-2") == 0))
     {
 	pos_T   sp = curwin->w_cursor;