diff --git a/src/mbyte.c b/src/mbyte.c
index 2f4edd5..78230f6 100644
--- a/src/mbyte.c
+++ b/src/mbyte.c
@@ -318,6 +318,7 @@
 {
     {"ansi",		IDX_LATIN_1},
     {"iso-8859-1",	IDX_LATIN_1},
+    {"iso-8859",	IDX_LATIN_1},
     {"latin2",		IDX_ISO_2},
     {"latin3",		IDX_ISO_3},
     {"latin4",		IDX_ISO_4},
@@ -4523,7 +4524,7 @@
 	}
 
 	// "iso-8859n" -> "iso-8859-n"
-	if (STRNCMP(p, "iso-8859", 8) == 0 && p[8] != '-')
+	if (STRNCMP(p, "iso-8859", 8) == 0 && isdigit(p[8]))
 	{
 	    STRMOVE(p + 9, p + 8);
 	    p[8] = '-';
diff --git a/src/testdir/test_options.vim b/src/testdir/test_options.vim
index 2af13d9..9ba2ce4 100644
--- a/src/testdir/test_options.vim
+++ b/src/testdir/test_options.vim
@@ -445,6 +445,31 @@
   call assert_fails('set t_#-&', 'E522:')
 endfunc
 
+func Test_set_encoding()
+  let save_encoding = &encoding
+
+  set enc=iso8859-1
+  call assert_equal('latin1', &enc)
+  set enc=iso8859_1
+  call assert_equal('latin1', &enc)
+  set enc=iso-8859-1
+  call assert_equal('latin1', &enc)
+  set enc=iso_8859_1
+  call assert_equal('latin1', &enc)
+  set enc=iso88591
+  call assert_equal('latin1', &enc)
+  set enc=iso8859
+  call assert_equal('latin1', &enc)
+  set enc=iso-8859
+  call assert_equal('latin1', &enc)
+  set enc=iso_8859
+  call assert_equal('latin1', &enc)
+  call assert_fails('set enc=iso8858', 'E474:')
+  call assert_equal('latin1', &enc)
+
+  let &encoding = save_encoding
+endfunc
+
 func CheckWasSet(name)
   let verb_cm = execute('verbose set ' .. a:name .. '?')
   call assert_match('Last set from.*test_options.vim', verb_cm)
diff --git a/src/version.c b/src/version.c
index 399aef9..23f45b5 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4439,
+/**/
     4438,
 /**/
     4437,