diff --git a/lib/cretonne/src/lib.rs b/lib/cretonne/src/lib.rs
index f34bed638b..ab7bb51f03 100644
--- a/lib/cretonne/src/lib.rs
+++ b/lib/cretonne/src/lib.rs
@@ -1,6 +1,8 @@
 //! Cretonne code generation library.
 
-#![deny(missing_docs)]
+#![deny(missing_docs,
+        trivial_numeric_casts,
+        unused_extern_crates)]
 
 pub use context::Context;
 pub use legalizer::legalize_function;
diff --git a/lib/filecheck/src/lib.rs b/lib/filecheck/src/lib.rs
index a189acebdb..4c8a242897 100644
--- a/lib/filecheck/src/lib.rs
+++ b/lib/filecheck/src/lib.rs
@@ -236,7 +236,9 @@
 //! This will match `"one, two"` , but not `"one,two"`. Without the `$()`, trailing whitespace
 //! would be trimmed from the pattern.
 
-#![deny(missing_docs)]
+#![deny(missing_docs,
+        trivial_numeric_casts,
+        unused_extern_crates)]
 
 pub use error::{Error, Result};
 pub use variable::{VariableMap, Value, NO_VARIABLES};
diff --git a/lib/frontend/src/lib.rs b/lib/frontend/src/lib.rs
index 9db5a4a34b..8d2de2237b 100644
--- a/lib/frontend/src/lib.rs
+++ b/lib/frontend/src/lib.rs
@@ -142,7 +142,9 @@
 //! }
 //! ```
 
-#![deny(missing_docs)]
+#![deny(missing_docs,
+        trivial_numeric_casts,
+        unused_extern_crates)]
 
 extern crate cretonne;
 
diff --git a/lib/native/src/lib.rs b/lib/native/src/lib.rs
index 6cdb39a15e..d7c6a8d0ab 100644
--- a/lib/native/src/lib.rs
+++ b/lib/native/src/lib.rs
@@ -1,7 +1,9 @@
 //! Performs autodetection of the host for the purposes of running
 //! Cretonne to generate code to run on the same machine.
 
-#![deny(missing_docs)]
+#![deny(missing_docs,
+        trivial_numeric_casts,
+        unused_extern_crates)]
 
 extern crate cretonne;
 
diff --git a/lib/reader/src/lib.rs b/lib/reader/src/lib.rs
index 06a03dd6fe..85ea048950 100644
--- a/lib/reader/src/lib.rs
+++ b/lib/reader/src/lib.rs
@@ -3,7 +3,9 @@
 //! The cton_reader library supports reading .cton files. This functionality is needed for testing
 //! Cretonne, but is not essential for a JIT compiler.
 
-#![deny(missing_docs)]
+#![deny(missing_docs,
+        trivial_numeric_casts,
+        unused_extern_crates)]
 
 extern crate cretonne;
 
diff --git a/lib/wasm/src/lib.rs b/lib/wasm/src/lib.rs
index b5b79049fe..6e9a6a365a 100644
--- a/lib/wasm/src/lib.rs
+++ b/lib/wasm/src/lib.rs
@@ -9,7 +9,9 @@
 //!
 //! The main function of this module is [`translate_module`](fn.translate_module.html).
 
-#![deny(missing_docs)]
+#![deny(missing_docs,
+        trivial_numeric_casts,
+        unused_extern_crates)]
 
 extern crate wasmparser;
 extern crate cton_frontend;