diff --git a/tool/ports/mk/install.mk b/tool/ports/mk/install.mk
index 6fe5271abf..dec4984063 100644
--- a/tool/ports/mk/install.mk
+++ b/tool/ports/mk/install.mk
@@ -179,7 +179,8 @@ _svn_dir = $(call _assert,$(DIR($1)),Missing declaration of DIR($*))
 	$(VERBOSE)dir=$(call _svn_dir,$*);\
 		rm -rf $$dir; \
 		$(MSG_DOWNLOAD)$(URL($*)); \
-		svn export -q $(URL($*))@$(REV($*)) $$dir;
+		svn export --trust-server-cert --non-interactive \
+			-q $(URL($*))@$(REV($*)) $$dir;
 
 
 ##