diff --git a/src/cooling/grackle/cooling.c b/src/cooling/grackle/cooling.c
index 7b764728bd98c19e8c61312e30522a744569f305..dbf5052b37e247b178f4b2ef6778e1a8cfe524c8 100644
--- a/src/cooling/grackle/cooling.c
+++ b/src/cooling/grackle/cooling.c
@@ -1280,8 +1280,10 @@ void cooling_init_units(const struct unit_system* us,
 void cooling_init_grackle(struct cooling_function_data* cooling) {
 
 #ifdef SWIFT_DEBUG_CHECKS
-  /* enable verbose for grackle */
-  grackle_verbose = 1;
+  /* Enable verbose for grackle for rank 0 only. */
+  if (engine_rank == 0) {
+    grackle_verbose = 1;
+  }
 #endif
 
   chemistry_data* chemistry = &cooling->chemistry_data;