diff --git a/doc/retrace.md b/doc/retrace.md
index aaea59b..3ca198e 100644
--- a/doc/retrace.md
+++ b/doc/retrace.md
@@ -39,6 +39,8 @@
 Retracing tools supporting this versioning scheme should issue a warning when
 given mapping files with versions higher than the version supported by the tool.
 
+- Version 1.0 was introduced by R8 in version 3.1.21
+
 ### Source File
 
 The source file information states what source file a class originated from.
diff --git a/src/main/java/com/android/tools/r8/retrace/RetraceUnknownMapVersionDiagnostic.java b/src/main/java/com/android/tools/r8/retrace/RetraceUnknownMapVersionDiagnostic.java
index 0a7a7bb..9c1142b 100644
--- a/src/main/java/com/android/tools/r8/retrace/RetraceUnknownMapVersionDiagnostic.java
+++ b/src/main/java/com/android/tools/r8/retrace/RetraceUnknownMapVersionDiagnostic.java
@@ -6,6 +6,7 @@
 
 import com.android.tools.r8.Diagnostic;
 import com.android.tools.r8.Keep;
+import com.android.tools.r8.Version;
 import com.android.tools.r8.origin.Origin;
 import com.android.tools.r8.position.Position;
 
@@ -31,7 +32,8 @@
   @Override
   public String getDiagnosticMessage() {
     return String.format(
-        "Map version '%s' is unknown or introduced later than this retrace version.", versionName);
+        "Map version '%s' is unknown or introduced later than retrace version '%s'.",
+        versionName, Version.getVersionString());
   }
 
   public static RetraceUnknownMapVersionDiagnostic create(String versionName) {