diff --git a/src/hydro/Gizmo/hydro.h b/src/hydro/Gizmo/hydro.h
index ba8a676ee46204545f9fb168c44c3d60968a3c2e..46d532a9002e50d8a57cb41798e4a987ce1d04be 100644
--- a/src/hydro/Gizmo/hydro.h
+++ b/src/hydro/Gizmo/hydro.h
@@ -484,6 +484,18 @@ __attribute__((always_inline)) INLINE static void hydro_kick_extra(
   p->conserved.energy += p->conserved.flux.energy;
 #endif
 
+#ifdef SWIFT_DEBUG_CHECKS
+  if (p->conserved.mass < 0.) {
+    error(
+        "Negative mass after conserved variables update (mass: %g, dmass: %g)!",
+        p->conserved.mass, p->conserved.flux.mass);
+  }
+
+  if (p->conserved.energy < 0.) {
+    error("Negative energy after conserved variables update!");
+  }
+#endif
+
   /* Add gravity. We only do this if we have gravity activated. */
   if (p->gpart) {
     /* Retrieve the current value of the gravitational acceleration from the
diff --git a/src/space.c b/src/space.c
index 625fe944c488c871d02b14c72d15051b3e53b3c4..a64d68cc61a356665ecdbd279fdb40bd38596ac0 100644
--- a/src/space.c
+++ b/src/space.c
@@ -523,7 +523,7 @@ void space_rebuild(struct space *s, int verbose) {
 
 /* Be verbose about this. */
 #ifdef SWIFT_DEBUG_CHECKS
-  if (s->e->nodeID == 0 || verbose) message("re)building space");
+  if (s->e->nodeID == 0 || verbose) message("(re)building space");
   fflush(stdout);
 #endif