diff --git a/src/gravity/Default/gravity.h b/src/gravity/Default/gravity.h
index c99c7ac8c86331bca9180856504992435893d175..98bc7edb4605c6958ab3e8bbcb8178d6c054a36f 100644
--- a/src/gravity/Default/gravity.h
+++ b/src/gravity/Default/gravity.h
@@ -145,6 +145,7 @@ __attribute__((always_inline)) INLINE static void gravity_init_gpart(
   gp->a_grav[0] = 0.f;
   gp->a_grav[1] = 0.f;
   gp->a_grav[2] = 0.f;
+  gp->last_output = SHRT_MAX;
 
 #ifdef SWIFT_GRAVITY_FORCE_CHECKS
   gp->potential_PM = 0.f;
diff --git a/src/hydro/Gadget2/hydro.h b/src/hydro/Gadget2/hydro.h
index 58df37689efc47533466b68622457c6cbb0e2553..e617dc78d6e0ffe43ec3d84a9d3e5a6ce9d8fd45 100644
--- a/src/hydro/Gadget2/hydro.h
+++ b/src/hydro/Gadget2/hydro.h
@@ -752,6 +752,7 @@ __attribute__((always_inline)) INLINE static void hydro_first_init_part(
   xp->a_grav[1] = 0.f;
   xp->a_grav[2] = 0.f;
   xp->entropy_full = p->entropy;
+  xp->last_output = SHRT_MAX;
 
   hydro_reset_acceleration(p);
   hydro_init_part(p, NULL);