diff --git a/src/doc/unstable-book/src/compiler-flags/profile.md b/src/doc/unstable-book/src/compiler-flags/profile.md
index 66d14fd09978f..452aca51532c9 100644
--- a/src/doc/unstable-book/src/compiler-flags/profile.md
+++ b/src/doc/unstable-book/src/compiler-flags/profile.md
@@ -18,4 +18,4 @@ cargo run
 ```
 
 Once you've built and run your program, files with the `gcno` (after build) and `gcda` (after execution) extensions will be created.
-You can parse them with [llvm-cov gcov](http://llvm.org/docs/CommandGuide/llvm-cov.html#llvm-cov-gcov) or [grcov](https://github.com/marco-c/grcov).
+You can parse them with [llvm-cov gcov](https://llvm.org/docs/CommandGuide/llvm-cov.html#llvm-cov-gcov) or [grcov](https://github.com/mozilla/grcov).