diff --git a/lib/reline/unicode.rb b/lib/reline/unicode.rb
index e25c0c82b6..b1e9d71c2a 100644
--- a/lib/reline/unicode.rb
+++ b/lib/reline/unicode.rb
@@ -51,7 +51,7 @@ def self.escape_for_print(str)
       else
         EscapedPairs[gr.ord] || gr
       end
-    }.join
+    }.join('')
   end
 
   def self.safe_encode(str, encoding)