diff --git a/artiq/firmware/libio/Cargo.toml b/artiq/firmware/libio/Cargo.toml
index 6aacf0c47..f4d1cbbb9 100644
--- a/artiq/firmware/libio/Cargo.toml
+++ b/artiq/firmware/libio/Cargo.toml
@@ -8,8 +8,8 @@ name = "io"
 path = "lib.rs"
 
 [dependencies]
-failure = { version = "0.1", default-features = false }
-failure_derive = { version = "0.1", default-features = false }
+failure = { version = "=0.1.1", default-features = false }
+failure_derive = { version = "=0.1.1", default-features = false }
 byteorder = { version = "1.0", default-features = false, optional = true }
 
 [features]