diff --git a/llvm.spec b/llvm.spec
index 201fc93..1208056 100644
--- a/llvm.spec
+++ b/llvm.spec
@@ -1,4 +1,5 @@
 # We are building with clang for faster/lower memory LTO builds.
+# See https://docs.fedoraproject.org/en-US/packaging-guidelines/#_compiler_macros
 %global toolchain clang
 
 # Components enabled if supported by target architecture: