diff --git a/src/engine.c b/src/engine.c
index 6e3556f5ce6032047ffd8d08302ef5599b7f179c..4c9fce2f43323f91c4f58fb3440b794a972cfec2 100644
--- a/src/engine.c
+++ b/src/engine.c
@@ -1828,10 +1828,10 @@ void engine_exchange_proxy_multipoles(struct engine *e) {
  *
  * @param e The #engine.
  */
-void engine_print_task_counts(struct engine *e) {
+void engine_print_task_counts(const struct engine *e) {
 
   const ticks tic = getticks();
-  struct scheduler *const sched = &e->sched;
+  const struct scheduler *sched = &e->sched;
   const int nr_tasks = sched->nr_tasks;
   const struct task *const tasks = sched->tasks;
 
@@ -1878,7 +1878,7 @@ void engine_print_task_counts(struct engine *e) {
  *
  * @return the estimated total number of tasks
  */
-int engine_estimate_nr_tasks(struct engine *e) {
+int engine_estimate_nr_tasks(const struct engine *e) {
 
   int tasks_per_cell = e->tasks_per_cell;
   if (tasks_per_cell > 0) return e->s->tot_cells * tasks_per_cell;
@@ -1887,8 +1887,7 @@ int engine_estimate_nr_tasks(struct engine *e) {
    * basically use a formula <n1>*ntopcells + <n2>*(totcells - ntopcells).
    * Where <n1> is the expected maximum tasks per top-level/super cell, and
    * <n2> the expected maximum tasks for all other cells. These should give
-   * a safe upper limit.
-   */
+   * a safe upper limit. */
   int n1 = 0;
   int n2 = 0;
   if (e->policy & engine_policy_hydro) {
diff --git a/src/engine.h b/src/engine.h
index 0d649e6e531ed39994c4e0ef90b92d6e758a2ecc..db4a67d8209295f9bbd230cd989a49ad35fc5ca4 100644
--- a/src/engine.h
+++ b/src/engine.h
@@ -444,7 +444,7 @@ int engine_is_done(struct engine *e);
 void engine_pin(void);
 void engine_unpin(void);
 void engine_clean(struct engine *e);
-int engine_estimate_nr_tasks(struct engine *e);
+int engine_estimate_nr_tasks(const struct engine *e);
 
 /* Function prototypes, engine_maketasks.c. */
 void engine_maketasks(struct engine *e);