diff --git a/site.mk b/site.mk
index 44fe0b9..036f14a 100644
--- a/site.mk
+++ b/site.mk
@@ -22,3 +22,5 @@ DEFAULT_GLUON_RELEASE := 0.4.2+0-exp$(shell date '+%Y%m%d')
 
 # Allow overriding the release number from the command line
 GLUON_RELEASE ?= $(DEFAULT_GLUON_RELEASE)
+
+GLUON_PRIORITY ?= 0