diff --git a/runoff.spec b/runoff.spec
index e4cfd426bd8ac8b6831f0296e9635df88d08777f..46dcc090aff75ed38406ec0480c8ad841e3f06bb 100644
--- a/runoff.spec
+++ b/runoff.spec
@@ -17,6 +17,7 @@ even: main.c
 
 # spinlock.h either
 # spinlock.c either
+right: spinlock.c  # mild preference
 even: proc.h  # mild preference
 
 # goal is to have two action-packed 2-page spreads,