diff --git a/Cargo.toml b/Cargo.toml
index 71fac86..1536077 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -28,6 +28,7 @@ default = ["clock"]
 clock = ["time"]
 
 [dependencies]
+libc = { version = "0.2", default-features = false }
 time = { version = "0.1.39", optional = true }
 num-integer = { version = "0.1.36", default-features = false }
 num-traits = { version = "0.2", default-features = false }