Added missing file extension

diff --git a/src/doc/src/reference/environment-variables.md b/src/doc/src/reference/environment-variables.md
index 305cb8901a05a5c33955862d4866fb7e668b2e41..c216b068c588b6927bfd59af97f401b6eba2fdc0 100644 (file)
--- a/src/doc/src/reference/environment-variables.md
+++ b/src/doc/src/reference/environment-variables.md
@@ -134,7 +134,7 @@ let out_dir = env::var("OUT_DIR").unwrap();
 [configuration]: https://doc.rust-lang.org/reference/attributes.html#conditional-compilation
 [clang]: http://clang.llvm.org/docs/CrossCompilation.html#target-triple
 [jobserver]: https://www.gnu.org/software/make/manual/html_node/Job-Slots.html
-[cargo-config]: reference/config
+[cargo-config]: reference/config.html
 
 ### Environment variables Cargo sets for 3rd party subcommands