diff --git a/ext/psych/extconf.rb b/ext/psych/extconf.rb
index 857f8e68..1e52ce8b 100644
--- a/ext/psych/extconf.rb
+++ b/ext/psych/extconf.rb
@@ -7,35 +7,75 @@
 
 dir_config 'libyaml'
 
-if enable_config("bundled-libyaml", false) || !(find_header('yaml.h') && find_library('yaml', 'yaml_get_version'))
-  # Embed libyaml since we could not find it.
+$VPATH << "$(srcdir)/yaml"
+$INCFLAGS << " -I$(srcdir)/yaml"
 
-  $VPATH << "$(srcdir)/yaml"
-  $INCFLAGS << " -I$(srcdir)/yaml"
+$srcs = Dir.glob("#{$srcdir}/{,yaml/}*.c").map {|n| File.basename(n)}.sort
 
-  $srcs = Dir.glob("#{$srcdir}/{,yaml/}*.c").map {|n| File.basename(n)}.sort
+header = 'yaml/yaml.h'
+header = "{$(VPATH)}#{header}" if $nmake
+if have_macro("_WIN32")
+  $CPPFLAGS << " -DYAML_DECLARE_STATIC -DHAVE_CONFIG_H"
+end
+
+have_header 'dlfcn.h'
+have_header 'inttypes.h'
+have_header 'memory.h'
+have_header 'stdint.h'
+have_header 'stdlib.h'
+have_header 'strings.h'
+have_header 'string.h'
+have_header 'sys/stat.h'
+have_header 'sys/types.h'
+have_header 'unistd.h'
+have_header 'unicode/ucol.h'
+
+find_header 'yaml.h'
+have_header 'config.h'
 
-  header = 'yaml/yaml.h'
-  header = "{$(VPATH)}#{header}" if $nmake
-  if have_macro("_WIN32")
-    $CPPFLAGS << " -DYAML_DECLARE_STATIC -DHAVE_CONFIG_H"
+##
+# ICU dependency
+#
+
+ldflags = cppflags = nil
+
+if RbConfig::CONFIG["host_os"] =~ /darwin/
+  begin
+    brew_prefix = `brew --prefix icu4c`.chomp
+    ldflags   = "#{brew_prefix}/lib"
+    cppflags  = "#{brew_prefix}/include"
+    pkg_conf  = "#{brew_prefix}/lib/pkgconfig"
+    # pkg_config should be less error prone than parsing compiler
+    # commandline options, but we need to set default ldflags and cpp flags
+    # in case the user doesn't have pkg-config installed
+    ENV['PKG_CONFIG_PATH'] ||= pkg_conf
+  rescue
   end
+end
 
-  have_header 'dlfcn.h'
-  have_header 'inttypes.h'
-  have_header 'memory.h'
-  have_header 'stdint.h'
-  have_header 'stdlib.h'
-  have_header 'strings.h'
-  have_header 'string.h'
-  have_header 'sys/stat.h'
-  have_header 'sys/types.h'
-  have_header 'unistd.h'
-
-  find_header 'yaml.h'
-  have_header 'config.h'
+dir_config 'icu', cppflags, ldflags
+
+pkg_config("icu-i18n")
+pkg_config("icu-io")
+pkg_config("icu-uc")
+
+$CXXFLAGS << ' -std=c++11' unless $CXXFLAGS.include?("-std=")
+
+unless have_library 'icui18n' and have_header 'unicode/ucnv.h'
+  STDERR.puts "\n\n"
+  STDERR.puts "***************************************************************************************"
+  STDERR.puts "*********** icu required (brew install icu4c or apt-get install libicu-dev) ***********"
+  STDERR.puts "***************************************************************************************"
+  exit(1)
 end
 
+have_library 'z' or abort 'libz missing'
+have_library 'icuuc' or abort 'libicuuc missing'
+have_library 'icudata' or abort 'libicudata missing'
+
+$CFLAGS << ' -Wall -funroll-loops'
+$CFLAGS << ' -Wextra -O0 -ggdb3' if ENV['DEBUG']
+
 create_makefile 'psych' do |mk|
   mk << "YAML_H = #{header}".strip << "\n"
 end
diff --git a/ext/psych/yaml/emitter.c b/ext/psych/yaml/emitter.c
index 796294cc..6a5d47fc 100644
--- a/ext/psych/yaml/emitter.c
+++ b/ext/psych/yaml/emitter.c
@@ -1,6 +1,7 @@
-
 #include "yaml_private.h"
 
+#include <unicode/utf8.h>
+#include <unicode/uchar.h>
 /*
  * Flush the buffer if needed.
  */
@@ -416,6 +417,43 @@ yaml_emitter_increase_indent(yaml_emitter_t *emitter,
     return 1;
 }
 
+/*
+ * Checks if given utf-8 encoded code point represent printable character.
+ */
+
+static inline int
+yaml_emitter_is_printable(yaml_string_t string)
+{
+    unsigned char octet;
+    unsigned int width;
+    unsigned int value;
+
+    octet = string.pointer[0];
+    width = (octet & 0x80) == 0x00 ? 1 :
+            (octet & 0xE0) == 0xC0 ? 2 :
+            (octet & 0xF0) == 0xE0 ? 3 :
+            (octet & 0xF8) == 0xF0 ? 4 : 0;
+    value = (octet & 0x80) == 0x00 ? octet & 0x7F :
+            (octet & 0xE0) == 0xC0 ? octet & 0x1F :
+            (octet & 0xF0) == 0xE0 ? octet & 0x0F :
+            (octet & 0xF8) == 0xF0 ? octet & 0x07 : 0;
+    for (int k = 1; k < (int)width; k ++) {
+        octet = string.pointer[k];
+        value = (value << 6) + (octet & 0x3F);
+    }
+    return (((string).pointer[0] == 0x0A)
+            || ((string).pointer[0] >= 0x20 && (string).pointer[0] <= 0x7E)
+            || ((string).pointer[0] == 0xC2 && (string).pointer[1] >= 0xA0)
+            || ((string).pointer[0] > 0xC2 && (string).pointer[0] < 0xED)
+            || ((string).pointer[0] == 0xED && (string).pointer[1] < 0xA0)
+            || ((string).pointer[0] == 0xEE)
+            || ((string).pointer[0] == 0xEF
+                && !((string).pointer[1] == 0xBB && (string).pointer[2] == 0xBF)
+                && !((string).pointer[1] == 0xBF
+                     && ((string).pointer[2] == 0xBE || (string).pointer[2] == 0xBF)))
+            || u_isprint(value));
+}
+
 /*
  * State dispatcher.
  */
@@ -1598,7 +1636,7 @@ yaml_emitter_analyze_scalar(yaml_emitter_t *emitter,
             }
         }
 
-        if (!IS_PRINTABLE(string)
+        if (!yaml_emitter_is_printable(string)
                 || (!IS_ASCII(string) && !emitter->unicode)) {
             special_characters = 1;
         }
@@ -2061,7 +2099,7 @@ yaml_emitter_write_double_quoted_scalar(yaml_emitter_t *emitter,
 
     while (string.pointer != string.end)
     {
-        if (!IS_PRINTABLE(string) || (!emitter->unicode && !IS_ASCII(string))
+        if (!yaml_emitter_is_printable(string) || (!emitter->unicode && !IS_ASCII(string))
                 || IS_BOM(string) || IS_BREAK(string)
                 || CHECK(string, '"') || CHECK(string, '\\'))
         {
diff --git a/ext/psych/yaml/yaml_private.h b/ext/psych/yaml/yaml_private.h
index 266a6bd3..84c7208d 100644
--- a/ext/psych/yaml/yaml_private.h
+++ b/ext/psych/yaml/yaml_private.h
@@ -258,30 +258,6 @@ yaml_string_join(
 
 #define IS_ASCII(string)    IS_ASCII_AT((string),0)
 
-/*
- * Check if the character can be printed unescaped.
- */
-
-#define IS_PRINTABLE_AT(string,offset)                                          \
-    (((string).pointer[offset] == 0x0A)         /* . == #x0A */                 \
-     || ((string).pointer[offset] >= 0x20       /* #x20 <= . <= #x7E */         \
-         && (string).pointer[offset] <= 0x7E)                                   \
-     || ((string).pointer[offset] == 0xC2       /* #0xA0 <= . <= #xD7FF */      \
-         && (string).pointer[offset+1] >= 0xA0)                                 \
-     || ((string).pointer[offset] > 0xC2                                        \
-         && (string).pointer[offset] < 0xED)                                    \
-     || ((string).pointer[offset] == 0xED                                       \
-         && (string).pointer[offset+1] < 0xA0)                                  \
-     || ((string).pointer[offset] == 0xEE)                                      \
-     || ((string).pointer[offset] == 0xEF      /* #xE000 <= . <= #xFFFD */      \
-         && !((string).pointer[offset+1] == 0xBB        /* && . != #xFEFF */    \
-             && (string).pointer[offset+2] == 0xBF)                             \
-         && !((string).pointer[offset+1] == 0xBF                                \
-             && ((string).pointer[offset+2] == 0xBE                             \
-                 || (string).pointer[offset+2] == 0xBF))))
-
-#define IS_PRINTABLE(string)    IS_PRINTABLE_AT((string),0)
-
 /*
  * Check if the character at the specified position is NUL.
  */
diff --git a/test/psych/test_string.rb b/test/psych/test_string.rb
index 0dc34b30..f9568ef4 100644
--- a/test/psych/test_string.rb
+++ b/test/psych/test_string.rb
@@ -178,6 +178,16 @@ def test_string_with_base_60
       assert_equal '01:03:05', Psych.load(yaml)
     end
 
+    def test_unicode_string
+      yaml = Psych.dump '😃'.encode('utf-8')
+      assert_match "😃", yaml
+    end
+
+    def test_original_issue_unicode_string
+      yaml = Psych.dump '🇩🇪'.encode('utf-8')
+      assert_match "🇩🇪", yaml
+    end
+
     def test_nonascii_string_as_binary
       string = "hello \x80 world!".dup
       string.force_encoding 'ascii-8bit'