Index: Makefile
===================================================================
--- Makefile	(revision 486580)
+++ Makefile	(working copy)
@@ -20,7 +20,7 @@
 
 USES=		autoreconf compiler:c++11-lang gmake libtool localbase pathfix pkgconfig
 
-CFLAGS+=	-DGOOGLE_PROTOBUF_NO_RTTI -I${WRKSRC}/src
+CFLAGS+=	-DGOOGLE_PROTOBUF_NO_RTTI -I${WRKSRC}/src -D_THREAD_SAFE
 CONFIGURE_ENV=	CC_FOR_BUILD="${CC}" \
 		CFLAGS_FOR_BUILD="${CFLAGS}" \
 		CPPFLAGS_FOR_BUILD="${CPPFLAGS}" \