diff --git a/Makefile b/Makefile
index 910f4713ef..da0cfda3e8 100644
--- a/Makefile
+++ b/Makefile
@@ -246,7 +246,7 @@ endif
 
 CFLAGS = -g -O2 -Wall
 LDFLAGS =
-ALL_CFLAGS = $(CFLAGS)
+ALL_CFLAGS = $(CPPFLAGS) $(CFLAGS)
 ALL_LDFLAGS = $(LDFLAGS)
 STRIP ?= strip
 
diff --git a/config.mak.in b/config.mak.in
index 6008ac9f1b..7eb6f59eb1 100644
--- a/config.mak.in
+++ b/config.mak.in
@@ -3,6 +3,7 @@
 
 CC = @CC@
 CFLAGS = @CFLAGS@
+CPPFLAGS = @CPPFLAGS@
 LDFLAGS = @LDFLAGS@
 CC_LD_DYNPATH = @CC_LD_DYNPATH@
 AR = @AR@