diff --git a/main/command/src/main/scala/sbt/internal/server/Serialization.scala b/main/command/src/main/scala/sbt/internal/server/Serialization.scala
index e399cd450..f7da4b0f9 100644
--- a/main/command/src/main/scala/sbt/internal/server/Serialization.scala
+++ b/main/command/src/main/scala/sbt/internal/server/Serialization.scala
@@ -56,7 +56,7 @@ object Serialization {
       implicit val formats = DefaultFormats
 
       (json \ "type").toOption match {
-        case Some(JString("command_exec")) =>
+        case Some(JString("exec")) =>
           (json \ "command_line").toOption match {
             case Some(JString(cmd)) => Right(Execution(cmd))
             case _                  => Left("Missing or invalid command_line field")