diff --git a/Makefile b/Makefile
index 17ee0c536..d217737d2 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@
 # Makefile for Deluge
 #
 PYVER=`python -c "import sys; print sys.version[:3]"`
-PREFIX = /usr
+PREFIX ?= /usr
 
 all:
 	python setup.py build