diff --git a/Library/Homebrew/dev-cmd/test-bot.rb b/Library/Homebrew/dev-cmd/test-bot.rb
index aee80a609a8ffa7a734dad9748f5234a697a12aa..754123d5a6a28c0a851a1bda71700196adb8edc8 100644
--- a/Library/Homebrew/dev-cmd/test-bot.rb
+++ b/Library/Homebrew/dev-cmd/test-bot.rb
@@ -1001,7 +1001,9 @@ module Homebrew
         invalid_xml_pat = /[\x00-\x08\x0B\x0C\x0E-\x1F\uFFFE\uFFFF]/
         output = output.gsub(invalid_xml_pat, "\uFFFD")
       else
-        output = output.delete("\000\a\b\e\f\x2\x1f")
+        # Invalid XML chars, as far as single-byte chars go
+        output = output.delete("\x00\x01\x02\x03\x04\x05\x06\x07\x08\x0b\x0c\x0e\x0f" \
+          "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f")
       end
 
       # Truncate to 1MB to avoid hitting CI limits