diff --git a/src/libsyntax_pos/hygiene.rs b/src/libsyntax_pos/hygiene.rs
index 658408519b9c7..be031ea98c9d2 100644
--- a/src/libsyntax_pos/hygiene.rs
+++ b/src/libsyntax_pos/hygiene.rs
@@ -13,7 +13,7 @@
 //! `[1]` Matthew Flatt, Ryan Culpepper, David Darais, and Robert Bruce Findler. 2012.
 //! *Macros that work together: Compile-time bindings, partial expansion,
 //! and definition contexts*. J. Funct. Program. 22, 2 (March 2012), 181-216.
-//! DOI=10.1017/S0956796812000093 <http://dx.doi.org/10.1017/S0956796812000093>
+//! DOI=10.1017/S0956796812000093 <https://doi.org/10.1017/S0956796812000093>
 
 use GLOBALS;
 use Span;