diff --git a/artiq/firmware/satman/Cargo.toml b/artiq/firmware/satman/Cargo.toml
index 92800d42c..8e68e41ce 100644
--- a/artiq/firmware/satman/Cargo.toml
+++ b/artiq/firmware/satman/Cargo.toml
@@ -22,4 +22,5 @@ log = { version = "0.3", default-features = false }
 
 [dependencies.compiler_builtins]
 git = "https://github.com/rust-lang-nursery/compiler-builtins"
+rev = "631b568"
 features = ["mem"]