diff --git a/owlps-listener/Makefile b/owlps-listener/Makefile
index 02687c1..fb08469 100644
--- a/owlps-listener/Makefile
+++ b/owlps-listener/Makefile
@@ -32,8 +32,9 @@ CFLAGS = -O2 -Wall -Wextra -Wstrict-prototypes \
 DEPFLAGS = -MMD
 XCFLAGS = $(CFLAGS) $(DEPFLAGS) $(WARN) $(HEADERS)
 PICFLAG = -fPIC
-OWLPSFLAGS = -D OWLPS_VERSION=\"$(OWLPS_VERSION)\" \
-	-D USE_CONFIG_FILE -lconfuse -D USE_PTHREAD -pthread
+OWLPSFLAGS = -D OWLPS_VERSION=\"$(OWLPS_VERSION)\"
+OWLPSFLAGS += -D USE_PTHREAD -pthread
+OWLPSFLAGS += -D USE_CONFIG_FILE -lconfuse
 #OWLPSFLAGS += -D NDEBUG
 LIBS = -L$(LIBOWLPS_DIR) -lowlps \
 	-L$(LIBOWLPSCLIENT_DIR) -lowlps-client \
diff --git a/owlps-listener/Makefile_atheros b/owlps-listener/Makefile_atheros
index fd3fb4d..efb6d81 100644
--- a/owlps-listener/Makefile_atheros
+++ b/owlps-listener/Makefile_atheros
@@ -42,8 +42,8 @@ LIBS = -lpcap -liw -lrt $(LOWLPSCLIENTA)
 STATIC_LIBS = -lm
 LATHEROS = -L$(TOOLCHAIN_USR)/lib -L$(TOOLCHAIN_USR_2)/lib
 IATHEROS = -I$(TOOLCHAIN_USR)/include -I$(TOOLCHAIN_USR_2)/include
-OWLPSFLAGS = -D OWLPS_VERSION=\"$(OWLPS_VERSION)\" \
-	-D USE_PTHREAD -pthread
+OWLPSFLAGS = -D OWLPS_VERSION=\"$(OWLPS_VERSION)\"
+OWLPSFLAGS += -D USE_PTHREAD -pthread
 #OWLPSFLAGS += -D USE_CONFIG_FILE -lconfuse
 #OWLPSFLAGS += -D NDEBUG
 LDFLAGS = $(OWLPSFLAGS) $(LIBS)
diff --git a/owlps-listener/Makefile_atheros_openwrt-10.03 b/owlps-listener/Makefile_atheros_openwrt-10.03
index d0e75d2..b9c8a52 100644
--- a/owlps-listener/Makefile_atheros_openwrt-10.03
+++ b/owlps-listener/Makefile_atheros_openwrt-10.03
@@ -46,8 +46,8 @@ LATHEROS = -L$(TOOLCHAIN1)/lib -L$(TOOLCHAIN1)/usr/lib \
 	-L$(TOOLCHAIN2)/usr/lib
 	#-L$(TOOLCHAIN2)/root-atheros/lib
 IATHEROS = -I$(TOOLCHAIN1)/usr/include -I$(TOOLCHAIN2)/usr/include
-OWLPSFLAGS = -D OWLPS_VERSION=\"$(OWLPS_VERSION)\" \
-	-D USE_PTHREAD -pthread
+OWLPSFLAGS = -D OWLPS_VERSION=\"$(OWLPS_VERSION)\"
+OWLPSFLAGS += -D USE_PTHREAD -pthread
 OWLPSFLAGS += -D USE_CONFIG_FILE -lconfuse
 #OWLPSFLAGS += -D NDEBUG
 LDFLAGS = $(OWLPSFLAGS) $(LIBS)