diff --git a/query/query.go b/query/query.go
index 9dd132ca..69b800cc 100644
--- a/query/query.go
+++ b/query/query.go
@@ -281,6 +281,10 @@ func evalConstants(q Q) Q {
 		if s.Regexp.Op == syntax.OpEmptyMatch {
 			return &Const{true}
 		}
+	case *Branch:
+		if s.Pattern == "" {
+			return &Const{true}
+		}
 	}
 	return q
 }