diff --git a/src/testdir/test_python3.vim b/src/testdir/test_python3.vim
index 20f9dc6..c044954 100644
--- a/src/testdir/test_python3.vim
+++ b/src/testdir/test_python3.vim
@@ -467,7 +467,10 @@
   python3 << trim eof
     s+='E'
   eof
-  call assert_equal('ABCDE', pyxeval('s'))
+  python3 << trimm
+s+='F'
+trimm
+  call assert_equal('ABCDEF', pyxeval('s'))
 endfunc
 
 " Test for the buffer range object