diff --git a/apps/Makefile b/apps/Makefile
index 949746a3..15ce0cc3 100644
--- a/apps/Makefile
+++ b/apps/Makefile
@@ -184,151 +184,151 @@ TARGETS = all clean
 $(TARGETS): %: $(patsubst %, %.%, $(SUBDIRS))
 
 $(foreach TGT, $(TARGETS), $(patsubst %, %.$(TGT), $(SUBDIRS))):
-	$(MAKE) -b -C $(subst ., , $@)
+	$(MAKE) -C $(subst ., , $@)
 
 .PHONY: lib
 lib: lib/Makefile Makefile $(BACNET_LIB_TARGET)
 
 $(BACNET_LIB_TARGET):
-	$(MAKE) -b -C lib
+	$(MAKE) -B -C lib
 
 .PHONY: gateway
 gateway: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C gateway
+	$(MAKE) -B -C $@
 
 .PHONY: abort
 abort: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: ack-alarm
 ack-alarm: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: dcc
 dcc: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: epics
 epics: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: error
 error: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: event
 event: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: getevent
 getevent: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: iam
 iam: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: iamrouter
 iamrouter: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: initrouter
 initrouter: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: whatisnetnum
 whatisnetnum: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: netnumis
 netnumis: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: mstpcap
 mstpcap:
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: mstpcrc
 mstpcrc:
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: ptransfer
 ptransfer: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: readprop
 readprop: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: readpropm
 readpropm: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: readbdt
 readbdt: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: readfdt
 readfdt: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: readfile
 readfile: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: readrange
 readrange: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: reinit
 reinit: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: scov
 scov: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: server
 server: $(BACNET_LIB_TARGET)
-	$(MAKE) -s -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: server-client
 server-client: $(BACNET_LIB_TARGET)
-	$(MAKE) -s -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: timesync
 timesync: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: uevent
 uevent: $(BACNET_LIB_TARGET)
-	$(MAKE) -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: whois
 whois: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: writebdt
 writebdt: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: writefile
 writefile: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: router
 router: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: router-ipv6
 router-ipv6: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: router-mstp
 router-mstp: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
 .PHONY: writepropm
 writepropm: $(BACNET_LIB_TARGET)
-	$(MAKE) -b -C $@
+	$(MAKE) -B -C $@
 
diff --git a/apps/gateway/Makefile b/apps/gateway/Makefile
index 9f9c28f8..6db86819 100644
--- a/apps/gateway/Makefile
+++ b/apps/gateway/Makefile
@@ -2,9 +2,13 @@
 
 # Executable file name
 TARGET = bacgateway
-# BACnet objects that are used with this app
+
+SRC := main.c
+
+BACNET_SRC_DIR ?= $(realpath ../../src)
 BACNET_OBJECT_DIR = $(BACNET_SRC_DIR)/bacnet/basic/object
-SRC = main.c \
+
+BACNET_OBJECT_SRC := \
 	$(BACNET_OBJECT_DIR)/gateway/gw_device.c \
 	$(BACNET_OBJECT_DIR)/acc.c \
 	$(BACNET_OBJECT_DIR)/ai.c \
@@ -53,9 +57,9 @@ BACNET_BASIC_SRC = \
 # TARGET_EXT is defined in apps/Makefile as .exe or nothing
 TARGET_BIN = ${TARGET}$(TARGET_EXT)
 
-SRCS = $(SRC) $(BACNET_SRC) $(BACNET_BASIC_SRC) $(BACNET_PORT_SRC)
+SRCS := $(SRC) $(BACNET_OBJECT_SRC) $(BACNET_BASIC_SRC)
 
-OBJS += ${SRCS:.c=.o}
+OBJS := $(SRCS:.c=.o)
 
 CFLAGS += -DBAC_ROUTING
 
diff --git a/apps/lib/Makefile b/apps/lib/Makefile
index 8278549f..eb04103f 100644
--- a/apps/lib/Makefile
+++ b/apps/lib/Makefile
@@ -86,7 +86,7 @@ endif
 BACNET_PORT_SRC += \
 	$(BACNET_SRC_DIR)/bacnet/datalink/dlenv.c \
 	$(BACNET_PORT_DIR)/mstimer-init.c \
-	$(BACNET_PORT_DIR)/datetime-init.c \
+	$(BACNET_PORT_DIR)/datetime-init.c
 
 BACNET_SRC ?= \
 	$(wildcard $(BACNET_SRC_DIR)/bacnet/*.c) \
diff --git a/src/bacnet/basic/object/gateway/gw_device.c b/src/bacnet/basic/object/gateway/gw_device.c
index 7d2f280b..afa4e3cc 100644
--- a/src/bacnet/basic/object/gateway/gw_device.c
+++ b/src/bacnet/basic/object/gateway/gw_device.c
@@ -616,6 +616,8 @@ int Routed_Device_Service_Approval(BACNET_SERVICES_SUPPORTED service,
     uint8_t invoke_id)
 {
     int len = 0;
+
+    (void)service_argument;
     switch (service) {
         case SERVICE_SUPPORTED_REINITIALIZE_DEVICE:
             /* If not the gateway device, we don't support RD */
@@ -643,5 +645,6 @@ int Routed_Device_Service_Approval(BACNET_SERVICES_SUPPORTED service,
             /* Everything else is a pass, at this time. */
             break;
     }
+
     return len;
 }