diff --git a/pjlib/build/pjlib_test.dsp b/pjlib/build/pjlib_test.dsp
index 3ba9536..d17af41 100644
--- a/pjlib/build/pjlib_test.dsp
+++ b/pjlib/build/pjlib_test.dsp
@@ -196,6 +196,10 @@
 # End Source File
 # Begin Source File
 
+SOURCE="..\src\pjlib-test\udp_echo_srv_ioqueue.c"
+# End Source File
+# Begin Source File
+
 SOURCE="..\src\pjlib-test\udp_echo_srv_sync.c"
 # End Source File
 # Begin Source File