diff --git a/src/option.c b/src/option.c
index cdd457b..a108c52 100644
--- a/src/option.c
+++ b/src/option.c
@@ -2956,7 +2956,7 @@
     (void)spell_check_msm();
     (void)spell_check_sps();
     (void)compile_cap_prog(curwin->w_s);
-    (void)did_set_spell_option(TRUE);
+    (void)did_set_spell_option();
 #endif
     // set cedit_key
     (void)did_set_cedit(NULL);
diff --git a/src/optionstr.c b/src/optionstr.c
index bf7135a..b1bb39a 100644
--- a/src/optionstr.c
+++ b/src/optionstr.c
@@ -3584,7 +3584,7 @@
 
     // If there is a window for this buffer in which 'spell' is set load the
     // wordlists.
-    return did_set_spell_option(TRUE);
+    return did_set_spell_option();
 }
 
 /*
@@ -3600,7 +3600,7 @@
 
     // If there is a window for this buffer in which 'spell' is set load the
     // wordlists.
-    return did_set_spell_option(FALSE);
+    return did_set_spell_option();
 }
 
 /*
diff --git a/src/proto/spell.pro b/src/proto/spell.pro
index 680bf34..a68de8f 100644
--- a/src/proto/spell.pro
+++ b/src/proto/spell.pro
@@ -45,6 +45,6 @@
 int expand_spelling(linenr_T lnum, char_u *pat, char_u ***matchp);
 int valid_spelllang(char_u *val);
 int valid_spellfile(char_u *val);
-char *did_set_spell_option(int is_spellfile);
+char *did_set_spell_option(void);
 char *compile_cap_prog(synblock_T *synblock);
 /* vim: set ft=c : */
diff --git a/src/spell.c b/src/spell.c
index 909d426..5a7720f 100644
--- a/src/spell.c
+++ b/src/spell.c
@@ -2250,7 +2250,7 @@
 	else
 	{
 	    // One entry in 'spellfile'.
-	    copy_option_part(&spf, spf_name, MAXPATHL - 5, ",");
+	    copy_option_part(&spf, spf_name, MAXPATHL - 4, ",");
 	    STRCAT(spf_name, ".spl");
 
 	    // If it was already found above then skip it.
@@ -4441,11 +4441,22 @@
     int
 valid_spellfile(char_u *val)
 {
-    char_u *s;
+    char_u	spf_name[MAXPATHL];
+    char_u	*spf;
+    char_u	*s;
+    int		l;
 
-    for (s = val; *s != NUL; ++s)
-	if (!vim_is_fname_char(*s))
+    spf = val;
+    while (*spf != NUL)
+    {
+	l = copy_option_part(&spf, spf_name, MAXPATHL, ",");
+	if (l >= MAXPATHL - 4 || l < 4
+				  || STRCMP(spf_name + l - 4, ".add") != 0)
 	    return FALSE;
+	for (s = spf_name; *s != NUL; ++s)
+	    if (!vim_is_fname_char(*s))
+		return FALSE;
+    }
     return TRUE;
 }
 
@@ -4454,22 +4465,10 @@
  * Return an error message or NULL for success.
  */
     char *
-did_set_spell_option(int is_spellfile)
+did_set_spell_option(void)
 {
     char    *errmsg = NULL;
     win_T   *wp;
-    int	    l;
-
-    if (is_spellfile)
-    {
-	l = (int)STRLEN(curwin->w_s->b_p_spf);
-	if (l > 0 && (l < 4
-			|| STRCMP(curwin->w_s->b_p_spf + l - 4, ".add") != 0))
-	    errmsg = e_invalid_argument;
-    }
-
-    if (errmsg != NULL)
-	return errmsg;
 
     FOR_ALL_WINDOWS(wp)
 	if (wp->w_buffer == curbuf && wp->w_p_spell)
diff --git a/src/testdir/gen_opt_test.vim b/src/testdir/gen_opt_test.vim
index 0d27760..4ca3c09 100644
--- a/src/testdir/gen_opt_test.vim
+++ b/src/testdir/gen_opt_test.vim
@@ -146,7 +146,11 @@
       \ 'sessionoptions': [['', 'blank', 'help,options,slash'], ['xxx']],
       \ 'showcmdloc': [['last', 'statusline', 'tabline'], ['xxx']],
       \ 'signcolumn': [['', 'auto', 'no'], ['xxx', 'no,yes']],
-      \ 'spellfile': [['', 'file.en.add', '/tmp/dir\ with\ space/en.utf-8.add'], ['xxx', '/tmp/file']],
+      \ 'spellfile': [['', 'file.en.add', 'xxx.en.add,yyy.gb.add,zzz.ja.add',
+      \		'/tmp/dir\ with\ space/en.utf-8.add',
+      \		'/tmp/dir\\,with\\,comma/en.utf-8.add'],
+      \		['xxx', '/tmp/file', ',file.en.add', 'xxx,yyy.en.add',
+      \		'xxx.en.add,yyy,zzz.ja.add']],
       \ 'spelllang': [['', 'xxx', 'sr@latin'], ['not&lang', "that\\\rthere"]],
       \ 'spelloptions': [['', 'camel'], ['xxx']],
       \ 'spellsuggest': [['', 'best', 'double,33'], ['xxx']],
diff --git a/src/testdir/test_spellfile.vim b/src/testdir/test_spellfile.vim
index 8abb680..dd12698 100644
--- a/src/testdir/test_spellfile.vim
+++ b/src/testdir/test_spellfile.vim
@@ -1154,7 +1154,7 @@
 " 'spellfile' accepts '@' on top of 'isfname'.
 def Test_spellfile_allow_at_character()
   mkdir('Xtest/the foo@bar,dir', 'p')
-  &spellfile = './Xtest/the foo@bar,dir/Xspellfile.add'
+  &spellfile = './Xtest/the foo@bar\,dir/Xspellfile.add'
   &spellfile = ''
   delete('Xtest', 'rf')
 enddef
diff --git a/src/version.c b/src/version.c
index c636211..2043563 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    783,
+/**/
     782,
 /**/
     781,