diff --git a/library/text/encoder/src/json_encoder.e b/library/text/encoder/src/json_encoder.e
index 84909edd..2e06a4f9 100644
--- a/library/text/encoder/src/json_encoder.e
+++ b/library/text/encoder/src/json_encoder.e
@@ -48,6 +48,7 @@ feature -- Encoder
 				if uc.is_character_8 then
 					c := uc.to_character_8
 					inspect c
+					when '%U' then Result.append_string ("\u0000")
 					when '%"' then Result.append_string ("\%"")
 					when '\' then Result.append_string ("\\")
 					when '%B' then Result.append_string ("\b")