--- Makefile.in
+++ Makefile.in
@@ -208,20 +208,20 @@
 	sed -e "s#\@RELPATH\@#$(RELPATH)#" \
 	-e "s#\@tls_LIB_FILE\@#$(tls_LIB_FILE)#" \
 	< $(srcdir)/pkgIndex.tcl.in > pkgIndex.tcl
-	$(INSTALL_DATA) pkgIndex.tcl $(pkglibdir)
+	$(INSTALL_DATA) pkgIndex.tcl $(DESTDIR)$(pkglibdir)
 
 #========================================================================
 # This rule installs platform-independent files, such as header files.
 #========================================================================
 
 install-libraries: libraries
-	$(mkinstalldirs) $(includedir)
-	@echo "Installing header files in $(includedir)"
+	$(mkinstalldirs) $(DESTDIR)$(includedir)
+	@echo "Installing header files in $(DESTDIR)$(includedir)"
 	@for i in $(GENERIC_HDRS) ; do \
 	    echo "Installing $$i" ; \
-	    $(INSTALL_DATA) $$i $(includedir) ; \
+	    $(INSTALL_DATA) $$i $(DESTDIR)$(includedir) ; \
 	done;
-	$(INSTALL_DATA) $(srcdir)/tls.tcl $(pkglibdir)
+	$(INSTALL_DATA) $(srcdir)/tls.tcl $(DESTDIR)$(pkglibdir)
 
 #========================================================================
 # Install documentation.  Unix manpages should go in the $(mandir)