diff --git a/ftp/libfilezilla/Makefile b/ftp/libfilezilla/Makefile
index d9377f7017af..d69893dc0472 100644
--- a/ftp/libfilezilla/Makefile
+++ b/ftp/libfilezilla/Makefile
@@ -20,4 +20,10 @@ USE_LDCONFIG=	yes
 GNU_CONFIGURE=	yes
 INSTALL_TARGET=	install-strip
 
-.include <bsd.port.mk>
+.include <bsd.port.pre.mk>
+
+.if ${CHOSEN_COMPILER_TYPE} == clang && ${COMPILER_VERSION} >= 191
+EXTRA_PATCHES= ${PATCHDIR}/extra-patch-lib_libfilezilla_string.hpp
+.endif
+
+.include <bsd.port.post.mk>