diff --git a/src/option.c b/src/option.c
index 32e97c9..b5f3a9a 100644
--- a/src/option.c
+++ b/src/option.c
@@ -7017,7 +7017,7 @@
 		    /* skip optional filename after 'k' and 's' */
 		    while (*s && *s != ',' && *s != ' ')
 		    {
-			if (*s == '\\')
+			if (*s == '\\' && s[1] != NUL)
 			    ++s;
 			++s;
 		    }
diff --git a/src/testdir/test_options.vim b/src/testdir/test_options.vim
index ce59ae1..31a87af 100644
--- a/src/testdir/test_options.vim
+++ b/src/testdir/test_options.vim
@@ -136,6 +136,15 @@
   call Check_dir_option('thesaurus')
 endfun
 
+func Test_complete()
+  " Trailing single backslash used to cause invalid memory access.
+  set complete=s\
+  new
+  call feedkeys("i\<C-N>\<Esc>", 'xt')
+  bwipe!
+  set complete&
+endfun
+
 func Test_set_completion()
   call feedkeys(":set di\<C-A>\<C-B>\"\<CR>", 'tx')
   call assert_equal('"set dictionary diff diffexpr diffopt digraph directory display', @:)
diff --git a/src/version.c b/src/version.c
index 9bbdf2e..dab99c7 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    333,
+/**/
     332,
 /**/
     331,