diff --git a/yamllint/linter.py b/yamllint/linter.py
index c35fc55..0fe2e0c 100644
--- a/yamllint/linter.py
+++ b/yamllint/linter.py
@@ -71,6 +71,7 @@ class LintProblem(object):
             "desc": self.desc,
             "rule": self.rule,
             "level": self.level,
+            "message": f"[{self.level}] {self.message}"
         }