diff --git a/pjsip-apps/build/samples.dsp b/pjsip-apps/build/samples.dsp
index a483182..3bdca95 100644
--- a/pjsip-apps/build/samples.dsp
+++ b/pjsip-apps/build/samples.dsp
@@ -114,6 +114,10 @@
 # End Source File
 # Begin Source File
 
+SOURCE=..\src\samples\mix.c
+# End Source File
+# Begin Source File
+
 SOURCE="..\src\samples\pjsip-perf.c"
 # End Source File
 # Begin Source File