diff --git a/daemon/Makefile b/daemon/Makefile
index 91ccf04d0..0c591759c 100644
--- a/daemon/Makefile
+++ b/daemon/Makefile
@@ -51,7 +51,7 @@ endif
 endif
 endif
 
-CFLAGS=		-g -Wall -Wstrict-prototypes -pthread -fno-strict-aliasing
+CFLAGS+=	-g -Wall -Wstrict-prototypes -pthread -fno-strict-aliasing
 CFLAGS+=	-std=c99
 CFLAGS+=	$(shell pkg-config --cflags glib-2.0)
 CFLAGS+=	$(shell pkg-config --cflags gthread-2.0)
diff --git a/recording-daemon/Makefile b/recording-daemon/Makefile
index 6e9a7051c..49f0999e3 100644
--- a/recording-daemon/Makefile
+++ b/recording-daemon/Makefile
@@ -1,6 +1,6 @@
 TARGET=		rtpengine-recording
 
-CFLAGS=		-g -Wall -Wstrict-prototypes -pthread -I. -I../lib/ -I../kernel-module/
+CFLAGS+=	-g -Wall -Wstrict-prototypes -pthread -I. -I../lib/ -I../kernel-module/
 CFLAGS+=	-std=c99 -fno-strict-aliasing
 CFLAGS+=	-D_GNU_SOURCE -D_POSIX_SOURCE -D_POSIX_C_SOURCE
 CFLAGS+=	$(shell pkg-config --cflags glib-2.0)