diff --git a/YSFGateway/APRSWriter.cpp b/YSFGateway/APRSWriter.cpp
index 0c25676..fd3ad40 100644
--- a/YSFGateway/APRSWriter.cpp
+++ b/YSFGateway/APRSWriter.cpp
@@ -39,7 +39,7 @@ m_suffix(suffix),
 m_aprsAddress(),
 m_aprsPort(port),
 m_aprsSocket()
-#if !defined(_WIN32) && !defined(_WIN64)
+#if defined(USE_GPSD)
 ,m_gpsdEnabled(false),
 m_gpsdAddress(),
 m_gpsdPort(),
@@ -78,7 +78,7 @@ 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());
 
@@ -90,7 +90,7 @@ 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) {
@@ -183,7 +183,7 @@ 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();
@@ -197,7 +197,7 @@ void CAPRSWriter::clock(unsigned int ms)
 			m_idTimer.setTimeout(20U * 60U);
 			m_idTimer.start();
 		}
-#if !defined(_WIN32) && !defined(_WIN64)
+#if defined(USE_GPSD)
 	}
 #endif
 }
@@ -206,7 +206,7 @@ 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);
@@ -278,6 +278,7 @@ void CAPRSWriter::sendIdFrameFixed()
 	m_aprsSocket.write((unsigned char*)output, (unsigned int)::strlen(output), m_aprsAddress, m_aprsPort);
 }
 
+#if defined(USE_GPSD)
 void CAPRSWriter::sendIdFrameMobile()
 {
 	if (!::gps_waiting(&m_gpsdData, 0))
@@ -367,4 +368,4 @@ void CAPRSWriter::sendIdFrameMobile()
 
 	m_aprsSocket.write((unsigned char*)output, (unsigned int)::strlen(output), m_aprsAddress, m_aprsPort);
 }
-
+#endif
diff --git a/YSFGateway/APRSWriter.h b/YSFGateway/APRSWriter.h
index f0e10ad..8ad4dff 100644
--- a/YSFGateway/APRSWriter.h
+++ b/YSFGateway/APRSWriter.h
@@ -71,7 +71,7 @@ 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/YSFGateway/Makefile b/YSFGateway/Makefile
index 8d37ea0..5056c0f 100644
--- a/YSFGateway/Makefile
+++ b/YSFGateway/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    = -lm -lpthread -lgps
 LDFLAGS = -g
 
diff --git a/YSFGateway/Version.h b/YSFGateway/Version.h
index eca752d..5f48e8f 100644
--- a/YSFGateway/Version.h
+++ b/YSFGateway/Version.h
@@ -19,6 +19,6 @@
 #if !defined(VERSION_H)
 #define	VERSION_H
 
-const char* VERSION = "20200605";
+const char* VERSION = "20200621";
 
 #endif