diff --git a/config.mk b/config.mk
index c6ae91d..e00a1e9 100644
--- a/config.mk
+++ b/config.mk
@@ -30,13 +30,13 @@ LIBS = -L$(X11LIB) -lm -lrt -lX11 -lutil -lXft -lXrender \
        `$(PKG_CONFIG) --libs freetype2`
 
 ifeq ($(OS),NetBSD)
-LIBS = $(LIBS) -Wl,-rpath,$(X11LIB)
+LIBS += -Wl,-rpath,$(X11LIB)
 endif
 
 # flags
 STCPPFLAGS = -DVERSION=\"$(VERSION)\" -D_XOPEN_SOURCE=600
 ifeq ($(OS),NetBSD)
-STCPPFLAGS = $(STCPPFLAGS) -D_BSD_SOURCE
+STCPPFLAGS += -D_BSD_SOURCE
 endif
 STCFLAGS = $(INCS) $(STCPPFLAGS) $(CPPFLAGS) $(CFLAGS) -mtune=native -march=native -O3 -pipe -fstack-protector-strong -fno-plt
 STLDFLAGS = $(LIBS) $(LDFLAGS)