diff --git a/NXDNGateway/APRSWriter.cpp b/NXDNGateway/APRSWriter.cpp
index fc1fc2c..cb67049 100644
--- a/NXDNGateway/APRSWriter.cpp
+++ b/NXDNGateway/APRSWriter.cpp
@@ -37,7 +37,7 @@ m_desc(),
 m_aprsAddress(),
 m_aprsPort(port),
 m_aprsSocket()
-#if !defined(_WIN32) && !defined(_WIN64)
+#if defined(USE_GPSD)
 ,m_gpsdEnabled(false),
 m_gpsdAddress(),
 m_gpsdPort(),
@@ -76,7 +76,7 @@ void CAPRSWriter::setStaticLocation(float latitude, float longitude, int height)
 
 void CAPRSWriter::setGPSDLocation(const std::string& address, const std::string& port)
 {
-#if !defined(_WIN32) && !defined(_WIN64)
+#if defined(USE_GPSD)
 	assert(!address.empty());
 	assert(!port.empty());
 
@@ -88,7 +88,7 @@ void CAPRSWriter::setGPSDLocation(const std::string& address, const std::string&
 
 bool CAPRSWriter::open()
 {
-#if !defined(_WIN32) && !defined(_WIN64)
+#if defined(USE_GPSD)
 	if (m_gpsdEnabled) {
 		int ret = ::gps_open(m_gpsdAddress.c_str(), m_gpsdPort.c_str(), &m_gpsdData);
 		if (ret != 0) {
@@ -127,7 +127,7 @@ void CAPRSWriter::clock(unsigned int ms)
 {
 	m_idTimer.clock(ms);
 
-#if !defined(_WIN32) && !defined(_WIN64)
+#if defined(USE_GPSD)
 	if (m_gpsdEnabled) {
 		if (m_idTimer.hasExpired()) {
 			sendIdFrameMobile();
@@ -141,7 +141,7 @@ void CAPRSWriter::clock(unsigned int ms)
 			m_idTimer.setTimeout(20U * 60U);
 			m_idTimer.start();
 		}
-#if !defined(_WIN32) && !defined(_WIN64)
+#if defined(USE_GPSD)
 	}
 #endif
 }
@@ -150,7 +150,7 @@ void CAPRSWriter::close()
 {
 	m_aprsSocket.close();
 
-#if !defined(_WIN32) && !defined(_WIN64)
+#if defined(USE_GPSD)
 	if (m_gpsdEnabled) {
 		::gps_stream(&m_gpsdData, WATCH_DISABLE, NULL);
 		::gps_close(&m_gpsdData);
@@ -222,6 +222,7 @@ void CAPRSWriter::sendIdFrameFixed()
 	write(output);
 }
 
+#if defined(USE_GPSD)
 void CAPRSWriter::sendIdFrameMobile()
 {
 	if (!::gps_waiting(&m_gpsdData, 0))
@@ -311,4 +312,4 @@ void CAPRSWriter::sendIdFrameMobile()
 
 	write(output);
 }
-
+#endif
diff --git a/NXDNGateway/APRSWriter.h b/NXDNGateway/APRSWriter.h
index 461d945..df51adc 100644
--- a/NXDNGateway/APRSWriter.h
+++ b/NXDNGateway/APRSWriter.h
@@ -70,7 +70,7 @@ private:
 	in_addr           m_aprsAddress;
 	unsigned int      m_aprsPort;
 	CUDPSocket        m_aprsSocket;
-#if !defined(_WIN32) && !defined(_WIN64)
+#if defined(USE_GPSD)
 	bool              m_gpsdEnabled;
 	std::string       m_gpsdAddress;
 	std::string       m_gpsdPort;
diff --git a/NXDNGateway/Makefile b/NXDNGateway/Makefile
index d9bc000..24cba48 100644
--- a/NXDNGateway/Makefile
+++ b/NXDNGateway/Makefile
@@ -1,6 +1,12 @@
 CC      = gcc
 CXX     = g++
+
+# Use the following CFLAGS if you don't want to use gpsd.
 CFLAGS  = -g -O3 -Wall -std=c++0x -pthread
+
+# Use the following CFLAGS if you do want to use gpsd.
+CFLAGS  = -g -O3 -Wall -DUSE_GPSD -std=c++0x -pthread
+
 LIBS    = -lpthread -lgps
 LDFLAGS = -g