diff --git a/src/globals.h b/src/globals.h
index bbc12cea38..8cc93857d7 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -1699,8 +1699,7 @@ EXTERN char e_const_option[]	INIT(= N_("E996: Cannot lock an option"));
 EXTERN char e_unknown_option[]	INIT(= N_("E113: Unknown option: %s"));
 EXTERN char e_letunexp[]	INIT(= N_("E18: Unexpected characters in :let"));
 EXTERN char e_reduceempty[]	INIT(= N_("E998: Reduce of an empty %s with no initial value"));
-// TODO: Change Error Number
-EXTERN char e_no_dict_key[]	INIT(= N_("E999: Dictionary with key \"%s\" required"));
+EXTERN char e_no_dict_key[]	INIT(= N_("E857: Dictionary key \"%s\" required"));
 #endif
 #ifdef FEAT_QUICKFIX
 EXTERN char e_readerrf[]	INIT(= N_("E47: Error while reading errorfile"));
diff --git a/src/testdir/test_functions.vim b/src/testdir/test_functions.vim
index cefeaf7f90..d0686eff34 100644
--- a/src/testdir/test_functions.vim
+++ b/src/testdir/test_functions.vim
@@ -1958,6 +1958,7 @@ func Test_readdirex_sort()
   let files = readdirex('Xdir2', 1, #{sort: 'none'})->map({-> v:val.name})
   let unsorted = copy(files)
   call assert_equal(['README.txt', 'Readme.txt', 'readme.txt'], sort(files), 'unsorted')
+  call assert_fails("call readdirex('Xdir2', 1, #{slort: 'none'})", 'E857: Dictionary key "sort" required')
 
   " 3) sort by case (same as default)
   let files = readdirex('Xdir2', 1, #{sort: 'case'})->map({-> v:val.name})
diff --git a/src/version.c b/src/version.c
index d69b5608fb..57b092a370 100644
--- a/src/version.c
+++ b/src/version.c
@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    990,
 /**/
     989,
 /**/