diff --git a/lib/psych/visitors/yaml_tree.rb b/lib/psych/visitors/yaml_tree.rb
index 9c2c4aa4..42382770 100644
--- a/lib/psych/visitors/yaml_tree.rb
+++ b/lib/psych/visitors/yaml_tree.rb
@@ -293,6 +293,9 @@ def visit_String o
         style = Nodes::Scalar::PLAIN
         tag   = nil
 
+        # the checks below match ASCII regexps, which UTF-16/32 strings cannot match against
+        o = o.encode(Encoding::UTF_8) unless o.encoding.ascii_compatible?
+
         if binary?(o)
           o     = [o].pack('m0')
           tag   = '!binary' # FIXME: change to below when syck is removed
diff --git a/test/psych/test_encoding.rb b/test/psych/test_encoding.rb
index 0a31a680..9009fcf6 100644
--- a/test/psych/test_encoding.rb
+++ b/test/psych/test_encoding.rb
@@ -55,6 +55,15 @@ def test_transcode_utf16be
       assert_equal str, loaded
     end
 
+    def test_dump_non_ascii_compatible_encoding
+      ['UTF-16LE', 'UTF-16BE', 'UTF-32LE', 'UTF-32BE'].each do |encoding|
+        ['', 'hello', "multi\nline", 'こんにちは！', 'yes', '<<', '0123'].each do |str|
+          assert_equal Psych.dump(str), Psych.dump(str.encode(encoding)),
+            "#{str.inspect} in #{encoding} should dump as it does in UTF-8"
+        end
+      end
+    end
+
     def test_io_shiftjis
       Tempfile.create(['shiftjis', 'yml'], :encoding => 'SHIFT_JIS') {|t|
         t.write '--- こんにちは！'