diff --git a/Makefile b/Makefile
index 0f5e098..abcb74d 100644
--- a/Makefile
+++ b/Makefile
@@ -3,7 +3,8 @@ VERSION	= 0.0.0
 SUBDIRS	= src/transport
 RM	= rm -f
 LN	= ln -f
-TAR	= tar -czvf
+TAR	= tar
+MKDIR	= mkdir -m 0755 -p
 
 
 all: subdirs
@@ -20,7 +21,7 @@ distclean:
 dist:
 	$(RM) -r -- $(PACKAGE)-$(VERSION)
 	$(LN) -s -- . $(PACKAGE)-$(VERSION)
-	@$(TAR) $(PACKAGE)-$(VERSION).tar.gz -- \
+	@$(TAR) -czvf $(PACKAGE)-$(VERSION).tar.gz -- \
 		$(PACKAGE)-$(VERSION)/src/transport/ssl.c \
 		$(PACKAGE)-$(VERSION)/src/transport/ssl4.c \
 		$(PACKAGE)-$(VERSION)/src/transport/ssl6.c \
@@ -33,10 +34,21 @@ dist:
 		$(PACKAGE)-$(VERSION)/project.conf
 	$(RM) -- $(PACKAGE)-$(VERSION)
 
+distcheck: dist
+	$(TAR) -xzvf $(PACKAGE)-$(VERSION).tar.gz
+	$(MKDIR) -- $(PACKAGE)-$(VERSION)/objdir
+	$(MKDIR) -- $(PACKAGE)-$(VERSION)/destdir
+	(cd "$(PACKAGE)-$(VERSION)" && $(MAKE) OBJDIR="$$PWD/objdir/")
+	(cd "$(PACKAGE)-$(VERSION)" && $(MAKE) OBJDIR="$$PWD/objdir/" DESTDIR="$$PWD/destdir" install)
+	(cd "$(PACKAGE)-$(VERSION)" && $(MAKE) OBJDIR="$$PWD/objdir/" DESTDIR="$$PWD/destdir" uninstall)
+	(cd "$(PACKAGE)-$(VERSION)" && $(MAKE) OBJDIR="$$PWD/objdir/" distclean)
+	(cd "$(PACKAGE)-$(VERSION)" && $(MAKE) dist)
+	$(RM) -r -- $(PACKAGE)-$(VERSION)
+
 install:
 	@for i in $(SUBDIRS); do (cd "$$i" && $(MAKE) install) || exit; done
 
 uninstall:
 	@for i in $(SUBDIRS); do (cd "$$i" && $(MAKE) uninstall) || exit; done
 
-.PHONY: all subdirs clean distclean dist install uninstall
+.PHONY: all subdirs clean distclean dist distcheck install uninstall
diff --git a/src/transport/Makefile b/src/transport/Makefile
index 77fd8e3..125c653 100644
--- a/src/transport/Makefile
+++ b/src/transport/Makefile
@@ -1,4 +1,5 @@
-TARGETS	= ssl.so ssl4.so ssl6.so
+TARGETS	= $(OBJDIR)ssl.so $(OBJDIR)ssl4.so $(OBJDIR)ssl6.so
+OBJDIR	=
 PREFIX	= /usr/local
 DESTDIR	=
 LIBDIR	= $(PREFIX)/lib
@@ -19,35 +20,35 @@ INSTALL	= install
 
 all: $(TARGETS)
 
-ssl_OBJS = ssl.o
+ssl_OBJS = $(OBJDIR)ssl.o
 ssl_CFLAGS = $(CPPFLAGSF) $(CPPFLAGS) $(CFLAGSF) $(CFLAGS)
 ssl_LDFLAGS = $(LDFLAGSF) $(LDFLAGS)
 
-ssl.so: $(ssl_OBJS)
-	$(CCSHARED) -o ssl.so $(ssl_OBJS) $(ssl_LDFLAGS)
+$(OBJDIR)ssl.so: $(ssl_OBJS)
+	$(CCSHARED) -o $(OBJDIR)ssl.so $(ssl_OBJS) $(ssl_LDFLAGS)
 
-ssl4_OBJS = ssl4.o
+ssl4_OBJS = $(OBJDIR)ssl4.o
 ssl4_CFLAGS = $(CPPFLAGSF) $(CPPFLAGS) $(CFLAGSF) $(CFLAGS)
 ssl4_LDFLAGS = $(LDFLAGSF) $(LDFLAGS)
 
-ssl4.so: $(ssl4_OBJS)
-	$(CCSHARED) -o ssl4.so $(ssl4_OBJS) $(ssl4_LDFLAGS)
+$(OBJDIR)ssl4.so: $(ssl4_OBJS)
+	$(CCSHARED) -o $(OBJDIR)ssl4.so $(ssl4_OBJS) $(ssl4_LDFLAGS)
 
-ssl6_OBJS = ssl6.o
+ssl6_OBJS = $(OBJDIR)ssl6.o
 ssl6_CFLAGS = $(CPPFLAGSF) $(CPPFLAGS) $(CFLAGSF) $(CFLAGS)
 ssl6_LDFLAGS = $(LDFLAGSF) $(LDFLAGS)
 
-ssl6.so: $(ssl6_OBJS)
-	$(CCSHARED) -o ssl6.so $(ssl6_OBJS) $(ssl6_LDFLAGS)
+$(OBJDIR)ssl6.so: $(ssl6_OBJS)
+	$(CCSHARED) -o $(OBJDIR)ssl6.so $(ssl6_OBJS) $(ssl6_LDFLAGS)
 
-ssl.o: ssl.c common.h common.c
-	$(CC) $(ssl_CFLAGS) -c ssl.c
+$(OBJDIR)ssl.o: ssl.c common.h common.c
+	$(CC) $(ssl_CFLAGS) -o $(OBJDIR)ssl.o -c ssl.c
 
-ssl4.o: ssl4.c ssl.c common.h common.c
-	$(CC) $(ssl4_CFLAGS) -c ssl4.c
+$(OBJDIR)ssl4.o: ssl4.c ssl.c common.h common.c
+	$(CC) $(ssl4_CFLAGS) -o $(OBJDIR)ssl4.o -c ssl4.c
 
-ssl6.o: ssl6.c ssl.c common.h common.c
-	$(CC) $(ssl6_CFLAGS) -c ssl6.c
+$(OBJDIR)ssl6.o: ssl6.c ssl.c common.h common.c
+	$(CC) $(ssl6_CFLAGS) -o $(OBJDIR)ssl6.o -c ssl6.c
 
 clean:
 	$(RM) -- $(ssl_OBJS) $(ssl4_OBJS) $(ssl6_OBJS)
@@ -57,11 +58,11 @@ distclean: clean
 
 install: $(TARGETS)
 	$(MKDIR) $(DESTDIR)$(LIBDIR)/App/transport
-	$(INSTALL) -m 0644 ssl.so $(DESTDIR)$(LIBDIR)/App/transport/ssl.so
+	$(INSTALL) -m 0755 $(OBJDIR)ssl.so $(DESTDIR)$(LIBDIR)/App/transport/ssl.so
 	$(MKDIR) $(DESTDIR)$(LIBDIR)/App/transport
-	$(INSTALL) -m 0644 ssl4.so $(DESTDIR)$(LIBDIR)/App/transport/ssl4.so
+	$(INSTALL) -m 0755 $(OBJDIR)ssl4.so $(DESTDIR)$(LIBDIR)/App/transport/ssl4.so
 	$(MKDIR) $(DESTDIR)$(LIBDIR)/App/transport
-	$(INSTALL) -m 0644 ssl6.so $(DESTDIR)$(LIBDIR)/App/transport/ssl6.so
+	$(INSTALL) -m 0755 $(OBJDIR)ssl6.so $(DESTDIR)$(LIBDIR)/App/transport/ssl6.so
 
 uninstall:
 	$(RM) -- $(DESTDIR)$(LIBDIR)/App/transport/ssl.so