diff --git a/martin/src/pg/errors.rs b/martin/src/pg/errors.rs
index b8b995ccb..4e83a2ab9 100644
--- a/martin/src/pg/errors.rs
+++ b/martin/src/pg/errors.rs
@@ -69,4 +69,7 @@ pub enum PgError {
 
     #[error(r#"Unable to get tile {2:#} with {:?} params from {1}: {0}"#, query_to_json(.3.as_ref()))]
     GetTileWithQueryError(#[source] TokioPgError, String, TileCoord, Option<UrlQuery>),
+
+    #[error("Validation error: {0}")]
+    ValidationError(String),
 }