diff --git a/build.symbian/pjmedia_audiodev.mmp b/build.symbian/pjmedia_audiodev.mmp
index 0c952ba..ccabc2f 100644
--- a/build.symbian/pjmedia_audiodev.mmp
+++ b/build.symbian/pjmedia_audiodev.mmp
@@ -12,6 +12,7 @@
 MACRO		PJ_SYMBIAN=1
 
 SOURCE		audiodev.c
+SOURCE		errno.c
 SOURCE		symb_aps_dev.cpp
 SOURCE		symb_mda_dev.cpp