diff --git a/acme_common/Cargo.toml b/acme_common/Cargo.toml
index 61e5726..31a3982 100644
--- a/acme_common/Cargo.toml
+++ b/acme_common/Cargo.toml
@@ -36,4 +36,4 @@ tinytemplate = "1.2"
 toml = "0.5"
 
 [target.'cfg(unix)'.dependencies]
-nix = "0.20"
+nix = "0.21"
diff --git a/acmed/Cargo.toml b/acmed/Cargo.toml
index 3e6e7fc..d8d86e2 100644
--- a/acmed/Cargo.toml
+++ b/acmed/Cargo.toml
@@ -33,7 +33,7 @@ tinytemplate = "1.2"
 toml = "0.5"
 
 [target.'cfg(unix)'.dependencies]
-nix = "0.20"
+nix = "0.21"
 
 [build-dependencies]
 serde = { version = "1.0", features = ["derive"] }