diff --git a/src/common_io.c b/src/common_io.c
index 3adda8000a9c4b074c35aa0da567b0c2093ac279..8846c8847b609cd84c5594cae38aea3edfcbf07d 100644
--- a/src/common_io.c
+++ b/src/common_io.c
@@ -896,6 +896,10 @@ void io_write_cell_offsets(hid_t h_grp, const int cdim[3], const double dim[3],
   }
 #endif
 
+  /* Abort if we don't have any cells yet (i.e. haven't constructed the space)
+   */
+  if (nr_cells == 0) return;
+
   double cell_width[3] = {width[0], width[1], width[2]};
 
   /* Temporary memory for the cell-by-cell information */
diff --git a/tests/testFeedback.c b/tests/testFeedback.c
index 56b4fedf7734ee25f67626bb2fd0aa7fc98571d3..1228a6fae056f41d9e4dd54a11065db336aad216 100644
--- a/tests/testFeedback.c
+++ b/tests/testFeedback.c
@@ -79,7 +79,8 @@ int main(int argc, char *argv[]) {
                       &hydro_properties, &cosmo);
 
   /* Init spart */
-  stars_first_init_spart(&sp, &stars_properties);
+  stars_first_init_spart(&sp, &stars_properties, /*with_cosmology=*/0, cosmo.a,
+                         cosmo.time);
 
   /* Define an initial stellar mass. (for use when calling the feedback
    * functions, the results are presented per initial stellar mass, so the
diff --git a/tests/testSelectOutput.c b/tests/testSelectOutput.c
index 8a08bcf58f0ece5645267a28f59c103506437165..4e16df60d882f2bde04d91ace429f5526ba5d7f2 100644
--- a/tests/testSelectOutput.c
+++ b/tests/testSelectOutput.c
@@ -83,7 +83,7 @@ int main(int argc, char *argv[]) {
   unsigned long long cpufreq = 0;
   clocks_set_cpufreq(cpufreq);
 
-  const char *base_name = "testSelectOutput";
+  // const char *base_name = "testSelectOutput";
   size_t Ngas = 0, Ngpart = 0, Ngpart_background = 0, Nspart = 0, Nbpart = 0;
   int flag_entropy_ICs = -1;
   int periodic = 1;
@@ -146,6 +146,8 @@ int main(int argc, char *argv[]) {
   /* pseudo initialization of the engine */
   message("Initialization of the engine.");
   struct engine e;
+  e.physical_constants = &prog_const;
+  sprintf(e.snapshot_base_name, "testSelectOutput");
   sprintf(e.run_name, "Select Output Test");
   select_output_engine_init(&e, &s, &cosmo, &param_file, &cooling,
                             &hydro_properties);
@@ -158,7 +160,7 @@ int main(int argc, char *argv[]) {
 
   /* write output file */
   message("Writing output.");
-  write_output_single(&e, base_name, &us, &us);
+  write_output_single(&e, &us, &us);
 
   /* Clean-up */
   message("Cleaning memory.");