--- a/src/tools/pegasus-kickstart/Makefile
+++ b/src/tools/pegasus-kickstart/Makefile
@@ -1,7 +1,6 @@
 INSTALL = install
 RM = rm -f
 CC = gcc
-CFLAGS = -O
 LD = $(CC)
 LOADLIBES = -lm
 SYSTEM = $(shell uname -s | tr '[a-z]' '[A-Z]' | tr -d '_ -/')
@@ -35,14 +34,14 @@
 else
 ifeq (x86_64,${MARCH})
 # new Intel/AMD 64bit architecture
-CFLAGS = -Wall -O2 -ggdb -m64
+CFLAGS += -Wall -O2 -ggdb -m64
 else
 ifeq (i686,${MARCH})
 # regular 32bit x86 architecture
-CFLAGS = -Wall -O2 -march=i686 -ggdb
+CFLAGS += -Wall -O2 -march=i686 -ggdb
 else
 # UNKNOWN ARCHITECTURE -- MAKE NO ASSUMPTIONS
-CFLAGS = -Wall -O2 -ggdb
+CFLAGS += -Wall -O2 -ggdb
 endif
 endif
 endif
@@ -70,16 +69,16 @@
 .PHONY: test
 
 %.o : %.c
-	$(CC) $(CFLAGS) $< -c -o $@
+	$(CC) $(CPPFLAGS) $(CFLAGS) $< -c -o $@
 
 all : pegasus-kickstart
 
 pegasus-kickstart: debug.o getif.o rwio.o tools.o useinfo.o mynss.o statinfo.o jobinfo.o limitinfo.o $(EXTRA_OBJ) machine.o appinfo.o parse.o mysystem.o mylist.o invoke.o pegasus-kickstart.o procinfo.o
-	$(LD) $(EXTRA_LDFLAGS) $(CFLAGS) $^ -o $@ $(LOADLIBES)
+	$(LD) $(LDFLAGS) $(CFLAGS) $^ -o $@ $(LOADLIBES)
 show-if: show-if.o getif.o debug.o rwio.o
-	$(LD) $(EXTRA_LDFLAGS) $(CFLAGS) $^ -o $@ $(LOADLIBES)
+	$(LD) $(LDFLAGS) $(CFLAGS) $^ -o $@ $(LOADLIBES)
 try-parse: try-parse.o parse.o debug.o rwio.o
-	$(LD) $(EXTRA_LDFLAGS) $(CFLAGS) $^ -o $@ $(LOADLIBES)
+	$(LD) $(LDFLAGS) $(CFLAGS) $^ -o $@ $(LOADLIBES)
 
 appinfo.o: appinfo.c getif.h rwio.h debug.h tools.h useinfo.h machine.h \
   jobinfo.h statinfo.h appinfo.h limitinfo.h mynss.h
--- a/src/tools/pegasus-cluster/Makefile
+++ b/src/tools/pegasus-cluster/Makefile
@@ -42,7 +42,7 @@
 endif
 
 ifeq (LINUX,${SYSTEM})
-CFLAGS	:= -Wall -O2 -ggdb
+CFLAGS	+= -Wall -O2 -ggdb
 ifeq (ia64,${MARCH})
 #
 # Linux IA64
@@ -77,7 +77,7 @@
 %.txt : %.1 ;
 	$(NROFF) $(TEXT) $< > $@
 %.o : %.c
-	$(CC) $(CFLAGS) $< -c -o $@
+	$(CC) $(CPPFLAGS) $(CFLAGS) $< -c -o $@
 
 all: pegasus-cluster
 
--- a/src/tools/pegasus-invoke/Makefile
+++ b/src/tools/pegasus-invoke/Makefile
@@ -57,15 +57,15 @@
 
 ifeq (LINUX,${SYSTEM})
 ifeq (ia64,${MARCH})
-CFLAGS  = -Wall -O2 -ggdb
+CFLAGS  += -Wall -O2 -ggdb
 else
 ifeq (x86_64,${MARCH})
-CFLAGS  = -Wall -O2 -ggdb -m64
+CFLAGS  += -Wall -O2 -ggdb -m64
 else
 ifeq (armv7l,${MARCH})
-CFLAGS	= -Wall -O2 -ggdb
+CFLAGS	+= -Wall -O2 -ggdb
 else
-CFLAGS  = -Wall -O2 -ggdb
+CFLAGS  += -Wall -O2 -ggdb
 #EXTRA_LDFLAGS += -static
 endif
 endif
@@ -80,7 +80,7 @@
 #CFLAGS += -D_POSIX_C_SOURCE=199506 -D__USE_XOPEN_EXTENDED
 
 %.o : %.c
-	$(CC) $(CFLAGS) $< -c -o $@
+	$(CC) $(CPPFLAGS) $(CFLAGS) $< -c -o $@
 
 all : pegasus-invoke
 
--- a/src/tools/pegasus-keg/Makefile
+++ b/src/tools/pegasus-keg/Makefile
@@ -4,7 +4,7 @@
 INSTALL = install
 RM      = rm -f
 CXX	= g++ -ffor-scope 
-CXXFLAGS = -O
+CXXFLAGS += -O
 LD      = $(CXX)
 LOADLIBES = -lm
 SYSTEM  = $(shell uname -s | tr '[a-z]' '[A-Z]' | tr -d '_ -/')
@@ -30,7 +30,7 @@
   EXTRA_INC += darwin.hh
 else
   ifeq (LINUX,${SYSTEM})
-    CXXFLAGS = -Wall -O2 -ggdb -DMACHINE_SPECIFIC=linux
+    CXXFLAGS += -Wall -O2 -ggdb -DMACHINE_SPECIFIC=linux
     EXTRA_OBJ += linux.o
     EXTRA_INC += linux.hh
     CFLAGS += $(shell getconf LFS_CFLAGS 2>>/dev/null)
@@ -46,7 +46,7 @@
 endif
 
 %.o : %.cc
-	$(CXX) $(CXXFLAGS) $< -c -o $@
+	$(CXX) $(CPPFLAGS) $(CXXFLAGS) $< -c -o $@
 
 all: pegasus-keg
 
