diff --git a/Library/Homebrew/extend/os/mac/keg_relocate.rb b/Library/Homebrew/extend/os/mac/keg_relocate.rb
index ec0ccb2399..3229bec9d6 100644
--- a/Library/Homebrew/extend/os/mac/keg_relocate.rb
+++ b/Library/Homebrew/extend/os/mac/keg_relocate.rb
@@ -230,13 +230,11 @@ module OS
         brewed_perl = runtime_dependencies&.any? { |dep| dep["full_name"] == "perl" && dep["declared_directly"] }
         perl_path = if brewed_perl || name == "perl"
           "#{HOMEBREW_PREFIX}/opt/perl/bin/perl"
-        elsif tab.built_on.present?
-          perl_path = "/usr/bin/perl#{tab.built_on["preferred_perl"]}"
-
-          # For `:all` bottles, we could have built this bottle with a Perl we don't have.
-          # Such bottles typically don't have strict version requirements.
-          perl_path = "/usr/bin/perl#{MacOS.preferred_perl_version}" unless File.exist?(perl_path)
-
+        elsif tab.built_on.present? &&
+              (preferred_perl_version = tab.built_on["preferred_perl"].presence) &&
+              preferred_perl_version.match?(/^\d+\.\d+$/) &&
+              (perl_path = "/usr/bin/perl#{preferred_perl_version}") &&
+              File.exist?(perl_path)
           perl_path
         else
           "/usr/bin/perl#{MacOS.preferred_perl_version}"