diff --git a/ftp/bftpd/Makefile b/ftp/bftpd/Makefile
index a2b68d47f79f..83551fec6003 100644
--- a/ftp/bftpd/Makefile
+++ b/ftp/bftpd/Makefile
@@ -13,6 +13,8 @@ LICENSE=	GPLv2
 
 GNU_CONFIGURE=	yes
 CONFIGURE_ARGS=	--enable-pam
+# Fix build with clang 11
+CFLAGS+=	-fcommon
 
 USES=		autoreconf gmake