diff --git a/packages/session/session-persistence/src/index.ts b/packages/session/session-persistence/src/index.ts
index 07a8819ca1..d579dc46d9 100644
--- a/packages/session/session-persistence/src/index.ts
+++ b/packages/session/session-persistence/src/index.ts
@@ -95,7 +95,10 @@ export abstract class SessionPersistence extends Service {
    */
   abstract locate(meta: SessionHeader): SessionLocation | undefined
 
-  /** Whether this backend exposes one verbatim raw artifact per session. */
+  /**
+   * Whether this backend exposes one verbatim raw artifact per session.
+   * A backend that declares `true` must override {@link readRaw}.
+   */
   abstract readonly supportsRawArtifacts: boolean
 
   /**