diff --git a/mk/install.mk b/mk/install.mk
index b2dc688..fe8485f 100644
--- a/mk/install.mk
+++ b/mk/install.mk
@@ -1,20 +1,20 @@
 # DESTDIR envvar is a way to install the application in a different root (for building packages for example).
-PREFIX    ?= $(DESTDIR)/usr/local/
+PREFIX    ?= /usr/local/
 BINDIR    ?= $(PREFIX)/bin
 SHAREDIR  ?= $(PREFIX)/share
 DOCDIR    ?= $(SHAREDIR)/doc/authd
 MANDIR    ?= $(SHAREDIR)/man
 
-install-authd: build-server ; install -D -m 555 ./bin/authd $(BINDIR)/authd
-install-authc: build-client ; install -D -m 555 ./bin/authc $(BINDIR)/authc
+install-authd: build-server ; install -D -m 555 ./bin/authd $(DESTDIR)$(BINDIR)/authd
+install-authc: build-client ; install -D -m 555 ./bin/authc $(DESTDIR)$(BINDIR)/authc
 install-binaries: install-authd install-authc
 
-install-man-authd:; install -D -m 444 ./man/authd.1 $(MANDIR)/authd.1
-install-man-authc:; install -D -m 444 ./man/authc.1 $(MANDIR)/authc.1
+install-man-authd:; install -D -m 444 ./man/authd.1 $(DESTDIR)$(MANDIR)/authd.1
+install-man-authc:; install -D -m 444 ./man/authc.1 $(DESTDIR)$(MANDIR)/authc.1
 install-man: install-man-authd install-man-authc
 
 doc:; crystal docs
-install-dev-doc: doc ; install -D docs/ $(DOCDIR)
+install-dev-doc: doc ; install -D docs/ $(DESTDIR)$(DOCDIR)
 
 # By default, dev documentation isn't installed.
 install: install-binaries install-man #install-dev-doc