diff --git a/src/if_ruby.c b/src/if_ruby.c
index d3ed781..543ee8a 100644
--- a/src/if_ruby.c
+++ b/src/if_ruby.c
@@ -1267,7 +1267,7 @@
     int	i;
     for (i = 0; i < RSTRING_LEN(str); i++)
     {
-	sprintf(buf, "%02X", RSTRING_PTR(str)[i]);
+	sprintf(buf, "%02X", (unsigned char)(RSTRING_PTR(str)[i]));
 	rb_str_concat(result, rb_str_new2(buf));
     }
     return result;
diff --git a/src/testdir/test_ruby.vim b/src/testdir/test_ruby.vim
index 5476e51..fe2afa6 100644
--- a/src/testdir/test_ruby.vim
+++ b/src/testdir/test_ruby.vim
@@ -306,6 +306,9 @@
   call assert_equal('foo',      RubyEval('Vim::evaluate("\"foo\"")'))
   call assert_equal('String',   RubyEval('Vim::evaluate("\"foo\"").class'))
 
+  call assert_equal('["\x01\xAB"]', RubyEval('Vim::evaluate("0z01ab").unpack("M")'))
+  call assert_equal('String',       RubyEval('Vim::evaluate("0z01ab").class'))
+
   call assert_equal('[1, 2]',   RubyEval('Vim::evaluate("[1, 2]")'))
   call assert_equal('Array',    RubyEval('Vim::evaluate("[1, 2]").class'))
 
@@ -324,6 +327,13 @@
   call assert_equal('FalseClass',RubyEval('Vim::evaluate("v:false").class'))
 endfunc
 
+func Test_Vim_blob()
+  call assert_equal('0z',         RubyEval('Vim::blob("")'))
+  call assert_equal('0z31326162', RubyEval('Vim::blob("12ab")'))
+  call assert_equal('0z00010203', RubyEval('Vim::blob("\x00\x01\x02\x03")'))
+  call assert_equal('0z8081FEFF', RubyEval('Vim::blob("\x80\x81\xfe\xff")'))
+endfunc
+
 func Test_Vim_evaluate_list()
   call setline(line('$'), ['2 line 2'])
   ruby Vim.command("normal /^2\n")
diff --git a/src/version.c b/src/version.c
index b747925..8d22ca9 100644
--- a/src/version.c
+++ b/src/version.c
@@ -780,6 +780,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    977,
+/**/
     976,
 /**/
     975,