Index: editors/libreoffice/Makefile
===================================================================
--- editors/libreoffice/Makefile	(revision 423562)
+++ editors/libreoffice/Makefile	(working copy)
@@ -283,6 +283,8 @@
 .endif
 .else
 CXXFLAGS_WARN=	-Wshadow -Woverloaded-virtual
+# required to build with lang/gcc5
+CXXFLAGS += -D_GLIBCXX_USE_C99=1 -include cstdio
 .endif
 
 pre-configure: