diff --git a/src/eval.c b/src/eval.c
index f645e96..46a1963 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -7854,7 +7854,7 @@
     {"ceil",		1, 1, f_ceil},
 #endif
     {"changenr",	0, 0, f_changenr},
-    {"char2nr",		1, 1, f_char2nr},
+    {"char2nr",		1, 2, f_char2nr},
     {"cindent",		1, 1, f_cindent},
     {"clearmatches",	0, 0, f_clearmatches},
     {"col",		1, 1, f_col},
@@ -8003,7 +8003,7 @@
     {"mzeval",		1, 1, f_mzeval},
 #endif
     {"nextnonblank",	1, 1, f_nextnonblank},
-    {"nr2char",		1, 1, f_nr2char},
+    {"nr2char",		1, 2, f_nr2char},
     {"or",		2, 2, f_or},
     {"pathshorten",	1, 1, f_pathshorten},
 #ifdef FEAT_FLOAT
@@ -9303,7 +9303,17 @@
 {
 #ifdef FEAT_MBYTE
     if (has_mbyte)
-	rettv->vval.v_number = (*mb_ptr2char)(get_tv_string(&argvars[0]));
+    {
+	int	utf8 = 0;
+
+	if (argvars[1].v_type != VAR_UNKNOWN)
+	    utf8 = get_tv_number_chk(&argvars[1], NULL);
+
+	if (utf8)
+	    rettv->vval.v_number = (*utf_ptr2char)(get_tv_string(&argvars[0]));
+	else
+	    rettv->vval.v_number = (*mb_ptr2char)(get_tv_string(&argvars[0]));
+    }
     else
 #endif
     rettv->vval.v_number = get_tv_string(&argvars[0])[0];
@@ -14360,7 +14370,16 @@
 
 #ifdef FEAT_MBYTE
     if (has_mbyte)
-	buf[(*mb_char2bytes)((int)get_tv_number(&argvars[0]), buf)] = NUL;
+    {
+	int	utf8 = 0;
+
+	if (argvars[1].v_type != VAR_UNKNOWN)
+	    utf8 = get_tv_number_chk(&argvars[1], NULL);
+	if (utf8)
+	    buf[(*utf_char2bytes)((int)get_tv_number(&argvars[0]), buf)] = NUL;
+	else
+	    buf[(*mb_char2bytes)((int)get_tv_number(&argvars[0]), buf)] = NUL;
+    }
     else
 #endif
     {