diff --git a/streamApp/tests/streamtestlib.tcl b/streamApp/tests/streamtestlib.tcl
index a31e705..ed62932 100644
--- a/streamApp/tests/streamtestlib.tcl
+++ b/streamApp/tests/streamtestlib.tcl
@@ -41,7 +41,7 @@ proc receiveHandler {sock} {
 }
 
 proc startioc {} {
-    global debug records protocol startup port sock ioc testname env streamversion
+    global debug records protocol startup port sock ioc testname env streamversion asynversion
     set fd [open test.db w]
     puts $fd $records
     close $fd
@@ -52,6 +52,9 @@ proc startioc {} {
     
     if [info exists streamversion] {
         puts $fd "#!/usr/local/bin/iocsh"
+        if [info exists asynversion] {
+            puts $fd "require asyn,$asynversion"
+        }
         puts $fd "require stream2,$streamversion"
     } else {
         puts $fd "#!../O.$env(EPICS_HOST_ARCH)/streamApp"
@@ -202,3 +205,7 @@ if {[lindex $argv 0] == "-sls"} {
     set streamversion [lindex $argv 1]
     set argv [lrange $argv 2 end]
 }
+if {[lindex $argv 0] == "-asyn"} {
+    set asynversion [lindex $argv 1]
+    set argv [lrange $argv 2 end]
+}