diff --git a/ChangeLog b/ChangeLog
index ab2940395..0ff1565e0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2016-12-04  Peter Stephenson  <p.w.stephenson@ntlworld.com>
+
+	* 40088: Test/D04parameter.ztst: attempt to make output from
+	interactive test more robust.
+
 2016-12-03  Barton E. Schaefer  <schaefer@zsh.org>
 
 	* unposted: Test/D04parameter.ztst: regression test for 40071
diff --git a/Test/D04parameter.ztst b/Test/D04parameter.ztst
index 834550cf5..9128c3c38 100644
--- a/Test/D04parameter.ztst
+++ b/Test/D04parameter.ztst
@@ -97,16 +97,17 @@
 
   PROMPT="" $ZTST_testdir/../Src/zsh -fis <<<'
   unsetopt PROMPT_SP
-  PS2="" PS3="" PS4="" RPS1="" RPS2=""
+  PS1="" PS2="" PS3="" PS4="" RPS1="" RPS2=""
+  exec 2>&1
   foo() {
       print ${1:?no arguments given}
       print not reached
   }
   foo
   print reached
-  '
+  ' 2>/dev/null
 0:interactive shell returns to top level on ${...?...} error
-?foo:1: 1: no arguments given
+*>*foo:1: 1: no arguments given
 >reached
 
   print ${set1:+word1} ${set1+word2} ${null1:+word3} ${null1+word4}