diff --git a/modules/log/shared/src/main/scala/LogSpan.scala b/modules/log/shared/src/main/scala/LogSpan.scala
index f5621a17..d8cb3419 100644
--- a/modules/log/shared/src/main/scala/LogSpan.scala
+++ b/modules/log/shared/src/main/scala/LogSpan.scala
@@ -75,7 +75,7 @@ private[log] final case class LogSpan[F[_]: Sync: Logger](
     putAny(
       "exit.case" -> "error".asJson,
       "exit.error.class" -> err.getClass.getName.asJson,
-      "exit.error.message" -> err.toString.asJson, // toString handles null message
+      "exit.error.message" -> Option(err.getMessage).map(_.asJson).getOrElse(Json.Null),
       "exit.error.stackTrace" -> err.getStackTrace.map(_.toString).asJson
     ) *> put(fields: _*)
 
diff --git a/modules/log/shared/src/test/scala/LogSuite.scala b/modules/log/shared/src/test/scala/LogSuite.scala
index a4115800..dc69306c 100644
--- a/modules/log/shared/src/test/scala/LogSuite.scala
+++ b/modules/log/shared/src/test/scala/LogSuite.scala
@@ -105,7 +105,7 @@ class LogSuite extends CatsEffectSuite {
                       |  ],
                       |  "exit.case" : "succeeded",
                       |  "exit.error.class" : "java.lang.RuntimeException",
-                      |  "exit.error.message" : "java.lang.RuntimeException: oops",
+                      |  "exit.error.message" : "oops",
                       |  "children" : [
                       |  ]
                       |}
@@ -118,7 +118,7 @@ class LogSuite extends CatsEffectSuite {
                    |  ],
                    |  "exit.case" : "succeeded",
                    |  "exit.error.class" : "java.lang.RuntimeException",
-                   |  "exit.error.message" : "java.lang.RuntimeException",
+                   |  "exit.error.message" : null,
                    |  "children" : [
                    |  ]
                    |}