diff --git a/src/bin/dhcp4/tests/parser_unittest.cc b/src/bin/dhcp4/tests/parser_unittest.cc
index ea31cd0fab6c4897e37a9fefea9e52c21616feed..60204afa826c47f3cd4ef5ee2f27acc6f4dc4d21 100644
--- a/src/bin/dhcp4/tests/parser_unittest.cc
+++ b/src/bin/dhcp4/tests/parser_unittest.cc
@@ -326,13 +326,13 @@ TEST(ParserTest, errors) {
     // JSON keywords
     testError("{ \"foo\": True }",
               Parser4Context::PARSER_JSON,
-              "<string>:1.10: Invalid character: T");
+              "<string>:1.10-13: JSON true reserved keyword is lower case only");
     testError("{ \"foo\": False }",
               Parser4Context::PARSER_JSON,
-              "<string>:1.10: Invalid character: F");
+              "<string>:1.10-14: JSON false reserved keyword is lower case only");
     testError("{ \"foo\": NULL }",
               Parser4Context::PARSER_JSON,
-              "<string>:1.10: Invalid character: N");
+              "<string>:1.10-13: JSON null reserved keyword is lower case only");
     testError("{ \"foo\": Tru }",
               Parser4Context::PARSER_JSON,
               "<string>:1.10: Invalid character: T");