diff --git a/src/jsx_utils.erl b/src/jsx_utils.erl
index 8f4dcf7..5c70797 100644
--- a/src/jsx_utils.erl
+++ b/src/jsx_utils.erl
@@ -245,6 +245,17 @@ json_escape(<<C/utf8, Rest/binary>>, Opts, Acc)
 %% any other legal codepoint
 json_escape(<<C/utf8, Rest/binary>>, Opts, Acc) ->
     json_escape(Rest, Opts, <<Acc/binary, C/utf8>>);
+%% if loose_unicode is true, replace illegal sequences with u+fffd
+%%  u+fffe and u+ffff
+json_escape(<<239, 191, X, Rest/binary>>, Opts=#opts{loose_unicode=true}, Acc)
+        when X == 190; X == 191 ->
+    json_escape(Rest, Opts, <<Acc/binary, 16#fffd/utf8>>);
+%% surrogates
+json_escape(<<237, X, _, Rest/binary>>, Opts=#opts{loose_unicode=true}, Acc)
+        when X >= 160 ->
+    json_escape(Rest, Opts, <<Acc/binary, 16#fffd/utf8>>);
+json_escape(<<_, Rest/binary>>, Opts=#opts{loose_unicode=true}, Acc) ->
+    json_escape(Rest, Opts, <<Acc/binary, 16#fffd/utf8>>);
 json_escape(<<>>, _Opts, Acc) ->
     Acc;
 json_escape(Rest, Opts, Acc) ->
@@ -334,6 +345,13 @@ binary_escape_test_() ->
                     #opts{escape_forward_slash=true}
                 ) =:= <<"\\/Date(1303502009425)\\/">>
             )
+        },
+        %% <<239, 191, 191>> is u+ffff
+        {"loose unicode",
+            ?_assert(json_escape(<<"hi there "/utf8, 239, 191, 191, "!"/utf8>>,
+                    #opts{loose_unicode=true}
+                ) =:= <<"hi there "/utf8, 16#fffd/utf8, "!"/utf8>>
+            )
         }
     ].