3 files changed, 11 insertions, 5 deletions
diff --git a/src/main/scala/logger/Logger.scala b/src/main/scala/logger/Logger.scala
index e37a45e4..e95ea643 100644
--- a/src/main/scala/logger/Logger.scala
+++ b/src/main/scala/logger/Logger.scala
@@ -361,7 +361,7 @@ object Logger {
     */
   def setOptions(inputAnnotations: AnnotationSeq): Unit = {
     val annotations =
-      Seq( AddDefaults, Checks )
+      Seq( new AddDefaults, Checks )
       .foldLeft(inputAnnotations)((a, p) => p.transform(a))
 
     val lopts = view[LoggerOptions](annotations)
diff --git a/src/main/scala/logger/phases/AddDefaults.scala b/src/main/scala/logger/phases/AddDefaults.scala
index f6daa811..3368283e 100644
--- a/src/main/scala/logger/phases/AddDefaults.scala
+++ b/src/main/scala/logger/phases/AddDefaults.scala
@@ -3,12 +3,15 @@
 package logger.phases
 
 import firrtl.AnnotationSeq
-import firrtl.options.Phase
+import firrtl.options.{Phase, PreservesAll}
 
 import logger.{LoggerOption, LogLevelAnnotation}
 
 /** Add default logger [[Annotation]]s */
-private [logger] object AddDefaults extends Phase {
+private [logger] class AddDefaults extends Phase with PreservesAll[Phase] {
+
+  override val prerequisites = Seq.empty
+  override val dependents = Seq.empty
 
   /** Add missing default [[Logger]] [[Annotation]]s to an [[AnnotationSeq]]
     * @param annotations input annotations
diff --git a/src/main/scala/logger/phases/Checks.scala b/src/main/scala/logger/phases/Checks.scala
index c706948c..1e1ccfe6 100644
--- a/src/main/scala/logger/phases/Checks.scala
+++ b/src/main/scala/logger/phases/Checks.scala
@@ -4,7 +4,7 @@ package logger.phases
 
 import firrtl.AnnotationSeq
 import firrtl.annotations.Annotation
-import firrtl.options.Phase
+import firrtl.options.{Dependency, Phase, PreservesAll}
 
 import logger.{LogLevelAnnotation, LogFileAnnotation, LoggerException}
 
@@ -12,7 +12,10 @@ import scala.collection.mutable
 
 /** Check that an [[firrtl.AnnotationSeq AnnotationSeq]] has all necessary [[firrtl.annotations.Annotation Annotation]]s
   * for a [[Logger]] */
-object Checks extends Phase {
+object Checks extends Phase with PreservesAll[Phase] {
+
+  override val prerequisites = Seq(Dependency[AddDefaults])
+  override val dependents = Seq.empty
 
   /** Ensure that an [[firrtl.AnnotationSeq AnnotationSeq]] has necessary [[Logger]] [[firrtl.annotations.Annotation
     * Annotation]]s