diff --git a/tasty/src/dotty/tools/tasty/TastyFormat.scala b/tasty/src/dotty/tools/tasty/TastyFormat.scala
index 3f516efe638c..1a534cd9d547 100644
--- a/tasty/src/dotty/tools/tasty/TastyFormat.scala
+++ b/tasty/src/dotty/tools/tasty/TastyFormat.scala
@@ -254,7 +254,7 @@ object TastyFormat {
   val MajorVersion: Int = 18
   val MinorVersion: Int = 0
 
-  /** Tags used to serialize names */
+  /** Tags used to serialize names, should update [[nameTagToString]] if a new constant is added */
   class NameTags {
     final val UTF8 = 1               // A simple name in UTF8 encoding.
 
@@ -286,6 +286,29 @@ object TastyFormat {
   }
   object NameTags extends NameTags
 
+  /**Should be kept in sync with [[NameTags]]. Converts constants to a String representing their identifier,
+   * or NotANameTag(tag) if unrecognised.
+   *
+   * For debugging purposes when unpickling names in a TASTy file.
+   */
+  def nameTagToString(tag: Int) = {
+    import NameTags._
+    tag match {
+      case UTF8 => "UTF8"
+      case QUALIFIED => "QUALIFIED"
+      case EXPANDED => "EXPANDED"
+      case EXPANDPREFIX => "EXPANDPREFIX"
+      case UNIQUE => "UNIQUE"
+      case DEFAULTGETTER => "DEFAULTGETTER"
+      case VARIANT => "VARIANT"
+      case SUPERACCESSOR => "SUPERACCESSOR"
+      case INLINEACCESSOR => "INLINEACCESSOR"
+      case OBJECTCLASS => "OBJECTCLASS"
+      case SIGNED => "SIGNED"
+      case id => s"NotANameTag($id)"
+    }
+  }
+
   // Position header
 
   final val SOURCE = 4