diff --git a/src/testdir/runtest.vim b/src/testdir/runtest.vim
index 56bb3d359d..89c1e3a5e0 100644
--- a/src/testdir/runtest.vim
+++ b/src/testdir/runtest.vim
@@ -281,6 +281,7 @@ let s:flaky_tests = [
       \ 'Test_close_callback()',
       \ 'Test_close_handle()',
       \ 'Test_close_lambda()',
+      \ 'Test_close_output_buffer()',
       \ 'Test_close_partial()',
       \ 'Test_collapse_buffers()',
       \ 'Test_communicate()',
diff --git a/src/version.c b/src/version.c
index 0231cc8ee6..a485b2851c 100644
--- a/src/version.c
+++ b/src/version.c
@@ -799,6 +799,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    600,
 /**/
     599,
 /**/