diff --git a/bin/piculet b/bin/piculet
index a7cef01..70e1552 100755
--- a/bin/piculet
+++ b/bin/piculet
@@ -95,7 +95,7 @@ ARGV.options do |opt|
     # Remap groups to exclude to regular expressions (if they're surrounded by '/')
     if options[:exclude_sgs]
       options[:exclude_sgs].map! do |name|
-        name =~ /\A\/(.*)\/\z/ ? Regexp.new($1) : Regexp.new("\A#{Regexp.escape(name)}\z")
+        name =~ /\A\/(.*)\/\z/ ? Regexp.new($1) : Regexp.new('\A' + Regexp.escape(name) + '\z')
       end
     end