diff --git a/src/testdir/test_ins_complete.vim b/src/testdir/test_ins_complete.vim
index f3c29d1..7d67e9f 100644
--- a/src/testdir/test_ins_complete.vim
+++ b/src/testdir/test_ins_complete.vim
@@ -4670,6 +4670,27 @@
   call feedkeys("Sze\<C-X>\<C-R>\<C-R>=string(complete_info(['mode']))\<CR>\<ESC>", "tx")
   call assert_equal("zero{'mode': 'register'}", getline(1))
 
+  " Test consecutive CTRL-X CTRL-R (adding mode)
+  " First CTRL-X CTRL-R should split into words, second should use full content
+  let @f = "hello world test complete"
+  call setline(1, "hel")
+  call cursor(1, 3)
+  call feedkeys("a\<C-X>\<C-R>\<C-N>\<Esc>", 'tx')
+  call assert_equal("hello", getline(1))
+
+  " Second consecutive CTRL-X CTRL-R should complete with full content
+  call setline(1, "hello")
+  call cursor(1, 5)
+  call feedkeys("a\<C-X>\<C-R>\<C-X>\<C-R>\<Esc>", 'tx')
+  call assert_equal("hello world test complete", getline(1))
+
+  " Test consecutive completion with multi-line register
+  let @g = "first line content\nsecond line here\nthird line data"
+  call setline(1, "first")
+  call cursor(1, 5)
+  call feedkeys("a\<C-X>\<C-R>\<C-X>\<C-R>\<Esc>", 'tx')
+  call assert_equal("first line content", getline(1))
+
   " Clean up
   bwipe!
   delfunc GetItems