diff --git a/serde/src/de/from_primitive.rs b/serde/src/de/from_primitive.rs
index 5bd3e531..fea4173d 100644
--- a/serde/src/de/from_primitive.rs
+++ b/serde/src/de/from_primitive.rs
@@ -10,6 +10,9 @@
 
 // Extracted from https://github.com/rust-num/num.
 
+// Rust 1.5 is unhappy that this private module is undocumented.
+#![allow(missing_docs)]
+
 use std::{usize, u8, u16, u32, u64};
 use std::{isize, i8, i16, i32, i64};
 use std::{f32, f64};