diff --git a/src/rule.h b/src/rule.h
index 5bbe95d7..7e9b7ffe 100644
--- a/src/rule.h
+++ b/src/rule.h
@@ -47,7 +47,7 @@ class Rule {
 
     std::vector<Variables::Variable *> *variables;
     int phase;
-    double rule_id;
+    long rule_id;
 
     Rule *chainedRule;
     bool chained;