diff --git a/core/src/main/scala/sbt/internal/librarymanagement/formats/GlobalLockFormat.scala b/core/src/main/scala/sbt/internal/librarymanagement/formats/GlobalLockFormat.scala
index fffd9b6a8..2e4ced132 100644
--- a/core/src/main/scala/sbt/internal/librarymanagement/formats/GlobalLockFormat.scala
+++ b/core/src/main/scala/sbt/internal/librarymanagement/formats/GlobalLockFormat.scala
@@ -15,7 +15,7 @@ trait GlobalLockFormat { self: BasicJsonProtocol =>
   implicit lazy val globalLockIsoString: IsoString[GlobalLock] =
     IsoString.iso(_ => "<lock>", _ => NoGlobalLock)
 
-  implicit lazy val GlobalLockFormat: JsonFormat[GlobalLock] = implicitly
+  implicit lazy val GlobalLockFormat: JsonFormat[GlobalLock] = isoStringFormat(globalLockIsoString)
 }
 
 private[sbt] object GlobalLockFormats {
diff --git a/core/src/main/scala/sbt/internal/librarymanagement/formats/LoggerFormat.scala b/core/src/main/scala/sbt/internal/librarymanagement/formats/LoggerFormat.scala
index 954b48127..f10fdb03f 100644
--- a/core/src/main/scala/sbt/internal/librarymanagement/formats/LoggerFormat.scala
+++ b/core/src/main/scala/sbt/internal/librarymanagement/formats/LoggerFormat.scala
@@ -12,5 +12,5 @@ trait LoggerFormat { self: BasicJsonProtocol =>
   implicit lazy val xsbtiLoggerIsoString: IsoString[Logger] =
     IsoString.iso(_ => "<logger>", _ => Null)
 
-  implicit lazy val LoggerFormat: JsonFormat[Logger] = implicitly
+  implicit lazy val LoggerFormat: JsonFormat[Logger] = isoStringFormat(implicitly)
 }