diff --git a/.travis.yml b/.travis.yml
index c366702..c270958 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,7 +1,11 @@
 language: rust
-rust: nightly
+rust:
+  - nightly
+  - beta
+  - stable
 script:
-  - cargo test
+  - cargo build
+  - "if [ $TRAVIS_RUST_VERSION = nightly ]; then cargo test; fi"
   - cargo doc
 after_success:
   - curl https://raw.githubusercontent.com/kmcallister/travis-doc-upload/master/travis-doc-upload.sh | sh
diff --git a/Cargo.toml b/Cargo.toml
index 60c34ec..d54277b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,4 +8,5 @@ repository = "https://github.com/servo/futf"
 description = "Handling fragments of UTF-8"
 
 [dependencies]
-mac = "0"
+mac = "0.0"
+debug_unreachable = "0.0"
diff --git a/src/lib.rs b/src/lib.rs
index 69433f5..13daba0 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -4,16 +4,18 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(core_intrinsics)]
 #![cfg_attr(test, feature(test, str_char, slice_bytes))]
 
+#[macro_use]
+extern crate debug_unreachable;
+
 #[macro_use]
 extern crate mac;
 
 #[cfg(test)]
 extern crate test as std_test;
 
-use std::{slice, char, intrinsics};
+use std::{slice, char};
 
 /// Meaning of a complete or partial UTF-8 codepoint.
 ///
@@ -131,7 +133,7 @@ unsafe fn decode(buf: &[u8]) -> Option<Meaning> {
                 | ((*buf.get_unchecked(3) & 0x3F) as u32);
             if n < 0x1_0000 { return None }  // Overlong
         }
-        _ => intrinsics::unreachable(),
+        _ => debug_unreachable!(),
     }
 
     char::from_u32(n).map(Meaning::Whole)