diff -up pbzip2-1.1.12/Makefile.flags pbzip2-1.1.12/Makefile

--- pbzip2-1.1.12/Makefile.flags	2015-09-09 16:10:11.389730644 +0200

+++ pbzip2-1.1.12/Makefile	2015-09-09 16:10:43.823872798 +0200

@@ -17,7 +17,7 @@ LDLIBS_PTHREAD = -lpthread

 # Optimization flags

-CXXFLAGS = -O2

+CXXFLAGS ?= -O2

 #CXXFLAGS += -g -Wall

 #CXXFLAGS += -ansi

@@ -50,11 +50,11 @@ CXXFLAGS += $(CXXFLAGS_PTHREAD)

 # Linker flags

-LDFLAGS =

+# LDFLAGS =

 # External libraries

-LDLIBS = -lbz2

+LDLIBS += -lbz2

 LDLIBS += $(LDLIBS_PTHREAD)