Import from libcore where possible
diff --git a/src/exception.rs b/src/exception.rs
index 125e484..e85bf61 100644
--- a/src/exception.rs
+++ b/src/exception.rs
@@ -1,4 +1,4 @@
-use std::fmt::{self, Debug, Display};
+use core::fmt::{self, Debug, Display};
 
 /// Exception thrown from an `extern "C"` function.
 #[derive(Debug)]