diff --git a/src/nvim/option.c b/src/nvim/option.c
index 74250e83e6..13aadb71bb 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -2997,9 +2997,10 @@ did_set_string_option (
         if (s[-1] == 'k' || s[-1] == 's') {
           /* skip optional filename after 'k' and 's' */
           while (*s && *s != ',' && *s != ' ') {
-            if (*s == '\\')
-              ++s;
-            ++s;
+            if (*s == '\\' && s[1] != NUL) {
+              s++;
+            }
+            s++;
           }
         } else {
           if (errbuf != NULL) {
diff --git a/src/nvim/testdir/test_options.vim b/src/nvim/testdir/test_options.vim
index 2ffe63787b..8a9d793a2e 100644
--- a/src/nvim/testdir/test_options.vim
+++ b/src/nvim/testdir/test_options.vim
@@ -103,3 +103,13 @@ func Test_keymap_valid()
   call assert_fails(":set kmp=trunc\x00name", "E544:")
   call assert_fails(":set kmp=trunc\x00name", "trunc")
 endfunc
+
+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
+
diff --git a/src/nvim/version.c b/src/nvim/version.c
index d4f9c0232f..7470b07655 100644
--- a/src/nvim/version.c
+++ b/src/nvim/version.c
@@ -619,7 +619,7 @@ static const int included_patches[] = {
   // 336,
   // 335,
   // 334,
-  // 333,
+  333,
   // 332,
   331,
   // 330,