--- Makefile.orig	2016-06-26 08:34:49.136904943 +0200
+++ Makefile	2016-06-26 08:35:46.448588504 +0200
@@ -154,7 +154,7 @@ CFLAGS := -O2 -fno-strict-aliasing -fomi
 		  -Wall -pipe -g -fwrapv
 CFLAGS += $(OSX_ARCH)
 else
-CFLAGS := -O2 -fno-strict-aliasing -fomit-frame-pointer \
+CFLAGS += -O2 -fno-strict-aliasing -fomit-frame-pointer \
 		  -Wall -pipe -g -ggdb -MMD -fwrapv
 endif
 
@@ -227,7 +227,7 @@ endif
 
 # Base LDFLAGS.
 ifeq ($(OSTYPE),Linux)
-LDFLAGS := -L/usr/lib -lm -ldl -rdynamic
+LDFLAGS += -L/usr/lib -lm -ldl -rdynamic
 else ifeq ($(OSTYPE),FreeBSD)
 LDFLAGS := -L/usr/local/lib -lm
 else ifeq ($(OSTYPE),OpenBSD)
