diff --git a/Makefile b/Makefile
index f378058..fa28272 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,8 @@
-DESTDIR = /usr/local/bin
 SUDOERSDIR = /private/etc/sudoers.d
 INSTALL_PATH_CBATTERY = $(DESTDIR)/cbattery
 INSTALL_PATH_VISUDO = $(SUDOERSDIR)/cbattery
+PREFIX ?= /usr/local
+DESTDIR = $(PREFIX)/bin
 
 all: install
 
@@ -10,10 +11,10 @@ install: $(INSTALL_PATH_CBATTERY) $(INSTALL_PATH_VISUDO)
 $(INSTALL_PATH_VISUDO): .visudo
 	@echo "Installing visudo file to $(SUDOERSDIR)"
 	@if ! test -d "$(SUDOERSDIR)"; then \
-		mkdir -p "$(SUDOERSDIR)"; \
+		sudo mkdir -p "$(SUDOERSDIR)"; \
 	fi
-	@cp $< $(SUDOERSDIR)/cbattery
-	@chmod 440 $(SUDOERSDIR)/cbattery
+	@sudo cp $< $(SUDOERSDIR)/cbattery
+	@sudo chmod 440 $(SUDOERSDIR)/cbattery
 
 $(INSTALL_PATH_CBATTERY): cbattery
 	@echo "Installing cbattery to $(DESTDIR)"