diff --git a/Library/Homebrew/extend/ENV/super.rb b/Library/Homebrew/extend/ENV/super.rb
index 08d71f4185..439321ed93 100644
--- a/Library/Homebrew/extend/ENV/super.rb
+++ b/Library/Homebrew/extend/ENV/super.rb
@@ -261,6 +261,9 @@ module Superenv
   sig { returns(String) }
   def determine_optflags
     Hardware::CPU.optimization_flags.fetch(effective_arch)
+  rescue KeyError
+    odebug "Building a bottle for custom architecture (#{effective_arch})..."
+    Hardware::CPU.arch_flag(effective_arch)
   end
 
   sig { returns(String) }
diff --git a/Library/Homebrew/formula_installer.rb b/Library/Homebrew/formula_installer.rb
index a629bbd545..4186efe132 100644
--- a/Library/Homebrew/formula_installer.rb
+++ b/Library/Homebrew/formula_installer.rb
@@ -395,10 +395,6 @@ class FormulaInstaller
 
     return if only_deps?
 
-    if build_bottle? && (arch = @bottle_arch) && Hardware::CPU.optimization_flags.exclude?(arch.to_sym)
-      raise CannotInstallFormulaError, "Unrecognized architecture for --bottle-arch: #{arch}"
-    end
-
     formula.deprecated_flags.each do |deprecated_option|
       old_flag = deprecated_option.old_flag
       new_flag = deprecated_option.current_flag