diff --git a/Agda.spec b/Agda.spec
index 074b0b4..d6acb2e 100644
--- a/Agda.spec
+++ b/Agda.spec
@@ -182,6 +182,7 @@ done
 # Begin cabal-rpm build:
 %ghc_libs_build %{subpkgs}
 %ifarch armv7hl
+# https://bugzilla.redhat.com/show_bug.cgi?id=991929
 %define cabal_configure_options --ghc-options="-O0"
 %endif
 %ghc_lib_build