diff --git a/src/engine.h b/src/engine.h
index 3613afd9f14705be74c00e60ff7e83c739f9339b..f80589ad3fad508f48a6fc3eda676a929b824c6e 100644
--- a/src/engine.h
+++ b/src/engine.h
@@ -160,7 +160,7 @@ struct engine {
   size_t updates, g_updates, s_updates;
 
   /* Properties of the previous step */
-  enum engine_step_properties step_props;
+  int step_props;
 
   /* Total numbers of particles in the system. */
   size_t total_nr_parts, total_nr_gparts;