--- a/mail/confvars.sh
+++ b/mail/confvars.sh
@@ -16,16 +16,20 @@ fi
 MOZ_COMPOSER=1
 if test "$OS_ARCH" = "WINNT"; then
   if ! test "$HAVE_64BIT_OS"; then
     MOZ_VERIFY_MAR_SIGNATURE=1
     MOZ_MAINTENANCE_SERVICE=1
   fi
 fi
 
+# Disable WebRTC as we don't use it currently and to work around bug 837618
+# for Mac
+MOZ_WEBRTC=
+
 MOZ_SAFE_BROWSING=1
 MOZ_MORK=1
 if test -z "$MOZ_INCOMPLETE_EXTERNAL_LINKAGE"; then
 MOZ_APP_COMPONENT_LIBS="xpautocomplete mailcomps $MAIL_COMPONENT $LDAP_COMPONENT $MORK_COMPONENT"
 MOZ_APP_COMPONENT_MODULES="MODULE(xpAutoComplete) MODULE(nsMailCompsModule) $MAIL_MODULE $LDAP_MODULE $MORK_MODULE"
 MOZ_APP_EXTRA_LIBS="$LDAP_LIBS"
 fi