diff --git a/Library/Homebrew/extend/ENV/super.rb b/Library/Homebrew/extend/ENV/super.rb
index 734eccb95d..c5bbe02cae 100644
--- a/Library/Homebrew/extend/ENV/super.rb
+++ b/Library/Homebrew/extend/ENV/super.rb
@@ -63,6 +63,7 @@ module Superenv
 
     self["HOMEBREW_ENV"] = "super"
     self["MAKEFLAGS"] ||= "-j#{determine_make_jobs}"
+    self["RUSTFLAGS"] = Hardware.rustflags_target_cpu
     self["PATH"] = determine_path
     self["PKG_CONFIG_PATH"] = determine_pkg_config_path
     self["PKG_CONFIG_LIBDIR"] = determine_pkg_config_libdir