Index: configs/mconfig.OpenBSD
--- configs/mconfig.OpenBSD.orig
+++ configs/mconfig.OpenBSD
@@ -11,7 +11,7 @@ SYSCONTROLSOCKET=/var/run/dinitctl
 
 # OpenBSD, tested with GCC 4.9.3 / Clang++ 4/5 and gmake:
 CXX=clang++
-CXXFLAGS=-std=c++11 -Os -Wall -fno-rtti
+override CXXFLAGS+=-std=c++11 -Wall -fno-rtti
 CPPFLAGS=
 LDFLAGS_BASE=
 LDFLAGS=$(LDFLAGS_BASE)
