diff --git a/hecl/extern/boo b/hecl/extern/boo
index 21f9fcf91..af4b1a452 160000
--- a/hecl/extern/boo
+++ b/hecl/extern/boo
@@ -1 +1 @@
-Subproject commit 21f9fcf914488a25926e781a99df4d4f19f4ee8a
+Subproject commit af4b1a4521a2e500088b1f358a474556493e2352