diff --git a/test/chan/powser1.go b/test/chan/powser1.go
index 93862003fdbe27..5357eec50fd65f 100644
--- a/test/chan/powser1.go
+++ b/test/chan/powser1.go
@@ -11,7 +11,7 @@
 // coefficients.  A denominator of zero signifies the end.
 // Original code in Newsqueak by Doug McIlroy.
 // See Squinting at Power Series by Doug McIlroy,
-//   http://www.cs.bell-labs.com/who/rsc/thread/squint.pdf
+//   https://swtch.com/~rsc/thread/squint.pdf
 
 package main
 
diff --git a/test/chan/powser2.go b/test/chan/powser2.go
index 8fa3b7e11cdf6f..fb1fb8518efc70 100644
--- a/test/chan/powser2.go
+++ b/test/chan/powser2.go
@@ -15,7 +15,7 @@
 // coefficients.  A denominator of zero signifies the end.
 // Original code in Newsqueak by Doug McIlroy.
 // See Squinting at Power Series by Doug McIlroy,
-//   http://www.cs.bell-labs.com/who/rsc/thread/squint.pdf
+//   https://swtch.com/~rsc/thread/squint.pdf
 
 package main