diff --git a/mysql-test/mysql-test-run.pl b/mysql-test/mysql-test-run.pl
index cf7e819809b..a866030bdf8 100755
--- a/mysql-test/mysql-test-run.pl
+++ b/mysql-test/mysql-test-run.pl
@@ -1217,6 +1217,19 @@ sub command_line_setup () {
   $path_ndb_testrun_log= "$opt_vardir/log/ndb_testrun.log";
 
   $path_snapshot= "$opt_tmpdir/snapshot_$opt_master_myport/";
+
+  if ( $opt_valgrind and $opt_debug )
+  {
+    # When both --valgrind and --debug is selected, send
+    # all output to the trace file, making it possible to
+    # see the exact location where valgrind complains
+    foreach my $mysqld (@{$master}, @{$slave})
+    {
+      my $sidx= $mysqld->{idx} ? "$mysqld->{idx}" : "";
+      $mysqld->{path_myerr}=
+	"$opt_vardir/log/" . $mysqld->{type} . "$sidx.trace";
+    }
+  }
 }
 
 sub datadir_list_setup () {