diff --git a/src/testdir/test_listdict.vim b/src/testdir/test_listdict.vim
index 8b2c27a..4c69476 100644
--- a/src/testdir/test_listdict.vim
+++ b/src/testdir/test_listdict.vim
@@ -1530,4 +1530,10 @@
   delfunc TestIdx
 endfunc
 
+func Test_extendnew_leak()
+  " This used to leak memory
+  for i in range(100) | silent! call extendnew([], [], []) | endfor
+  for i in range(100) | silent! call extendnew({}, {}, {}) | endfor
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab