diff --git a/README.md b/README.md
index cea36774..d65e19f4 100644
--- a/README.md
+++ b/README.md
@@ -17,8 +17,8 @@ Supported Python versions:
 
 Supported Rust version:
 
-* Rust 1.17.0-nightly or later
-* On Windows, we require rustc 1.17.0-nightly
+* Rust 1.19.0-nightly or later
+* On Windows, we require rustc 1.19.0-nightly
 
 ## Usage
 
@@ -75,7 +75,7 @@ features = ["extension-module"]
 **`src/lib.rs`**
 
 ```rust
-#![feature(proc_macro, specialization, associated_consts)]
+#![feature(proc_macro, specialization)]
 
 extern crate pyo3;
 use pyo3::{py, PyResult, Python, PyModule};
diff --git a/src/lib.rs b/src/lib.rs
index c498a32d..ee7d93d1 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,4 @@
-#![feature(specialization, proc_macro, const_fn, associated_consts)]
+#![feature(specialization, proc_macro, const_fn)]
 
 //! Rust bindings to the Python interpreter.
 //!
diff --git a/tests/test_buffer_protocol.rs b/tests/test_buffer_protocol.rs
index 6301a602..5a944b45 100644
--- a/tests/test_buffer_protocol.rs
+++ b/tests/test_buffer_protocol.rs
@@ -1,5 +1,5 @@
 #![allow(dead_code, unused_variables)]
-#![feature(proc_macro, specialization, associated_consts)]
+#![feature(proc_macro, specialization)]
 
 extern crate pyo3;
 
diff --git a/tests/test_class.rs b/tests/test_class.rs
index 315eeb28..f9b5e2e4 100644
--- a/tests/test_class.rs
+++ b/tests/test_class.rs
@@ -1,4 +1,4 @@
-#![feature(proc_macro, specialization, associated_consts)]
+#![feature(proc_macro, specialization)]
 #![allow(dead_code, unused_variables)]
 
 extern crate pyo3;
diff --git a/tests/test_slice.rs b/tests/test_slice.rs
index 181361a5..dad40516 100644
--- a/tests/test_slice.rs
+++ b/tests/test_slice.rs
@@ -1,4 +1,4 @@
-#![feature(proc_macro, specialization, associated_consts)]
+#![feature(proc_macro, specialization)]
 #![allow(dead_code, unused_variables)]
 
 extern crate pyo3;