autoload/lsp/completion.vim | 5 ++++-

diff --git a/autoload/lsp/completion.vim b/autoload/lsp/completion.vim
index b76070662754c1f8c0470dc7abf98f5762373361..799b0855b28a7b70b355edcee9e21fbb6986815f 100644
--- a/autoload/lsp/completion.vim
+++ b/autoload/lsp/completion.vim
@@ -126,7 +126,10 @@   if cItems->type() == v:t_list
     items = cItems
   else
     items = cItems.items
-    lspserver.completeItemsIsIncomplete = cItems.isIncomplete
+
+    if cItems->has_key("isIncomplete")
+      lspserver.completeItemsIsIncomplete = cItems.isIncomplete
+    endif
   endif
 
   # Get the keyword prefix before the current cursor column.