--- a/Makefile
+++ b/Makefile
@@ -4,11 +4,15 @@
 
 COBJS    = main-command.o unixtime.o gpx-read.o correlate.o exif-gps.o
 GOBJS    = main-gui.o gui.o unixtime.o gpx-read.o correlate.o exif-gps.o
-CFLAGS   = -Wall
-override CFLAGS += $(shell pkg-config --cflags libxml-2.0 gtk+-2.0) -I/usr/include/exiv2
-OFLAGS   = -Wall
-override OFLAGS += $(shell pkg-config --libs libxml-2.0 gtk+-2.0) -lm -lexiv2
-prefix   = /usr/local
+CFLAGS += $(shell ${PKG_CONFIG} --cflags libxml-2.0) -I/usr/include/exiv2
+CXXFLAGS += $(shell ${PKG_CONFIG} --cflags libxml-2.0) -I/usr/include/exiv2
+CLIBS = $(shell ${PKG_CONFIG} --libs libxml-2.0) -lm -lexiv2 -lstdc++
+ifdef BUILD_GUI
+CXXFLAGS += $(shell ${PKG_CONFIG} --cflags gtk+-2.0)
+CFLAGS += $(shell ${PKG_CONFIG} --cflags gtk+-2.0)
+CLIBS += $(shell ${PKG_CONFIG} --libs gtk+-2.0)
+endif
+prefix   ?= /usr/local
 bindir   = $(prefix)/bin
 datadir  = $(prefix)/share
 mandir   = $(datadir)/man
@@ -18,16 +22,16 @@
 all:	gpscorrelate gpscorrelate-gui gpscorrelate.1
 
 gpscorrelate: $(COBJS)
-	g++ $(OFLAGS) -o $@ $(COBJS)
+	$(CXX) $(LDFLAGS) $(COBJS) $(CLIBS) -o $@
 
 gpscorrelate-gui: $(GOBJS)
-	g++ $(OFLAGS) -o $@ $(GOBJS)
+	$(CXX) $(LDFLAGS) $(GOBJS) $(CLIBS) -o $@
 
-.c.o:
-	gcc $(CFLAGS) -c -o $*.o $<
+%.o: %.c
+	$(CC) -c -o $@ $< $(CFLAGS)
 
-.cpp.o:
-	g++ $(CFLAGS) -c -o $*.o $<
+%.o: %.cpp $(DEPS)
+	$(CXX) -c -o $@ $< $(CXXFLAGS)
 
 clean:
 	rm -f *.o gpscorrelate{,.exe} gpscorrelate-gui{,.exe}