diff --git a/bin/erb b/bin/erb
index 6a7ea7d593..2459680b88 100755
--- a/bin/erb
+++ b/bin/erb
@@ -137,8 +137,8 @@ EOU
 
     def set_encoding(extern, intern = nil)
       verbose, $VERBOSE = $VERBOSE, nil
-      Encoding.default_external = extern unless extern.nil? || extern.empty?
-      Encoding.default_internal = intern unless intern.nil? || intern.empty?
+      Encoding.default_external = extern unless extern.nil? || extern == ""
+      Encoding.default_internal = intern unless intern.nil? || intern == ""
       [$stdin, $stdout, $stderr].each do |io|
         io.set_encoding(extern, intern)
       end