Debian specific Makefile changes.
--- a/Makefile
+++ b/Makefile
@@ -14,28 +14,26 @@
 ## You should have received a copy of the GNU General Public License
 ## along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-PREFIX=/usr/local
-
 all:
 	echo "No compiling necessary."
 
 install:
 	echo '#!/usr/bin/env bash' > dr-theobold
-	echo pil $(PREFIX)/share/dr-theobold/dr-theobold.l -start-game >> dr-theobold
+	echo pil /usr/share/dr-theobold/dr-theobold.l -start-game >> dr-theobold
 	cp dr-theobold.l dr-theobold.l.tmp
-	sed -i s+tree.l+$(PREFIX)/share/dr-theobold/tree.l+ dr-theobold.l.tmp
-	mkdir -p $(PREFIX)/share/dr-theobold
-	cp tree.l $(PREFIX)/share/dr-theobold/tree.l
-	chmod 644 $(PREFIX)/share/dr-theobold/tree.l
-	cp dr-theobold.l.tmp $(PREFIX)/share/dr-theobold/dr-theobold.l
-	chmod 644 $(PREFIX)/share/dr-theobold/dr-theobold.l
-	mkdir -p $(PREFIX)/bin
-	cp dr-theobold $(PREFIX)/bin/dr-theobold
-	chmod 755 $(PREFIX)/bin/dr-theobold
+	sed -i s+tree.l+/usr/share/dr-theobold/tree.l+ dr-theobold.l.tmp
+	mkdir -p $(DESTDIR)/usr/share/dr-theobold
+	cp tree.l $(DESTDIR)/usr/share/dr-theobold/tree.l
+	chmod 644 $(DESTDIR)/usr/share/dr-theobold/tree.l
+	cp dr-theobold.l.tmp $(DESTDIR)/usr/share/dr-theobold/dr-theobold.l
+	chmod 644 $(DESTDIR)/usr/share/dr-theobold/dr-theobold.l
+	mkdir -p $(DESTDIR)/usr/games
+	cp dr-theobold $(DESTDIR)/usr/games/dr-theobold
+	chmod 755 $(DESTDIR)/usr/games/dr-theobold
 
 uninstall:
-	rm -rf $(PREFIX)/share/dr-theobold
-	rm -f $(PREFIX)/bin/dr-theobold
+	rm -rf $(DESTDIR)/usr/share/dr-theobold
+	rm -f $(DESTDIR)/usr/games/dr-theobold
 
 clean:
 	rm -f dr-theobold.l.tmp
