diff --git a/mozilla/config/config.mk b/mozilla/config/config.mk
index 66e31f9decc..329569acc8e 100644
--- a/mozilla/config/config.mk
+++ b/mozilla/config/config.mk
@@ -395,6 +395,7 @@ endif
 
 ifdef NECKO
 DEFINES += -DNECKO
+DEFINES += -DNET_SOCKET_PROVIDER_BUILD
 endif
 
 ifdef MOZ_DARK