diff --git a/lib/spring/json.rb b/lib/spring/json.rb
index 00f0dca3..c90c251d 100644
--- a/lib/spring/json.rb
+++ b/lib/spring/json.rb
@@ -13,6 +13,7 @@
 module Spring
   module JSON
     def self.load(string)
+      string = string.dup.force_encoding("utf-8") unless string.encoding == Encoding::UTF_8
       OkJson.decode(string)
     end
 
diff --git a/test/unit/json_test.rb b/test/unit/json_test.rb
index b9eecc05..3b5eb0ec 100644
--- a/test/unit/json_test.rb
+++ b/test/unit/json_test.rb
@@ -6,7 +6,12 @@ class JsonTest < ActiveSupport::TestCase
     assert_equal({"unicode_example"=>"©"}, Spring::JSON.load('{"unicode_example": "\u00A9"}'))
   end
 
+  test 'can decode binary strings with valid UTF8 characters' do
+    string = "{\"PS1\":\"\xEF\x90\x98 main \xEE\x9E\x91 v3.4.2\"}".b
+    assert_equal({"PS1"=>" main  v3.4.2"}, Spring::JSON.load(string))
+  end
+
   test 'can encode' do
     assert_equal('{}', Spring::JSON.dump({}))
-  end 
+  end
 end