diff --git a/crates/pinakes-core/src/storage/mod.rs b/crates/pinakes-core/src/storage/mod.rs
index 606dc61..5e5cdcd 100644
--- a/crates/pinakes-core/src/storage/mod.rs
+++ b/crates/pinakes-core/src/storage/mod.rs
@@ -1171,11 +1171,15 @@ pub trait StorageBackend: Send + Sync + 'static {
   async fn count_unresolved_links(&self) -> Result<u64>;
 
   /// Create a backup of the database to the specified path.
-  /// Default implementation returns unsupported; `SQLite` overrides with
-  /// VACUUM INTO.
+  ///
+  /// Only supported for SQLite (uses VACUUM INTO). PostgreSQL
+  /// deployments should use `pg_dump` directly; this method returns
+  /// `PinakesError::InvalidOperation` for unsupported backends.
   async fn backup(&self, _dest: &std::path::Path) -> Result<()> {
     Err(crate::error::PinakesError::InvalidOperation(
-      "backup not supported for this storage backend".to_string(),
+      "backup not supported for this storage backend; use pg_dump for \
+       PostgreSQL"
+        .to_string(),
     ))
   }
 }