diff --git a/src/testdir/test_retab.vim b/src/testdir/test_retab.vim
index 34ab7e1..2d96042 100644
--- a/src/testdir/test_retab.vim
+++ b/src/testdir/test_retab.vim
@@ -82,20 +82,34 @@
   call assert_fails('ret 80000000000000000000', 'E475:')
 endfunc
 
-" FIXME: the try/catch does not catch the interrupt
-func FIXME_Test_retab_endless()
+func RetabLoop()
+  while 1
+    set ts=4000
+    retab 4
+  endwhile
+endfunc
+
+func Test_retab_endless()
+  " inside try/catch we catch the error message
   new
   call setline(1, "\t0\t")
   let caught = 'no'
   try
-    while 1
-      set ts=4000
-      retab 4
-    endwhile
-  catch
+    call RetabLoop()
+  catch /E1240:/
     let caught = v:exception
   endtry
-  call assert_notequal('no', caught)
+  call assert_match('E1240:', caught)
+  bwipe!
+  set tabstop&
+endfunc
+
+func Test_nocatch_retab_endless()
+  " not inside try/catch an interrupt is generated to get out of loops
+  new
+  call setline(1, "\t0\t")
+  call assert_fails('call RetabLoop()', ['E1240:', 'Interrupted'])
+
   bwipe!
   set tabstop&
 endfunc