diff --git a/internal/indexer/service.go b/internal/indexer/service.go
index 4c9e2dd..e62de4a 100644
--- a/internal/indexer/service.go
+++ b/internal/indexer/service.go
@@ -376,6 +376,10 @@ func (s *service) LoadIndexerDefinitions() error {
 			return err
 		}
 
+		if d.Implementation == "" {
+			d.Implementation = "irc"
+		}
+
 		s.indexerDefinitions[d.Identifier] = d
 	}
 
@@ -430,6 +434,10 @@ func (s *service) LoadCustomIndexerDefinitions() error {
 			return err
 		}
 
+		if d.Implementation == "" {
+			d.Implementation = "irc"
+		}
+
 		s.indexerDefinitions[d.Identifier] = d
 
 		customCount++