diff --git a/org/qmckl_ao.org b/org/qmckl_ao.org
index 258ce00..c396bd8 100644
--- a/org/qmckl_ao.org
+++ b/org/qmckl_ao.org
@@ -5799,7 +5799,12 @@ qmckl_compute_ao_value_hpc_gaussian (const qmckl_context context,
 #endif
     for (int64_t ipoint=0 ; ipoint < point_num ; ++ipoint) {
 
-      memset(&ao_value[ipoint*ao_num], 0, ao_num*sizeof(double));
+      double* const ptr = &ao_value[ipoint*ao_num];
+      for (size_t k=0 ; k<ao_num ; ++k) {
+        ptr[k] = 0.;
+      }
+
+//      memset(&ao_value[ipoint*ao_num], 0, ao_num*sizeof(double));
 
       const double e_coord[3]  __attribute__((aligned(64))) =
         { coord[ipoint],
@@ -6590,7 +6595,12 @@ qmckl_compute_ao_vgl_hpc_gaussian (
 #endif
     for (int64_t ipoint=0 ; ipoint < point_num ; ++ipoint) {
 
-      memset(&ao_vgl[ipoint*ao_num*5], 0, 5*ao_num*sizeof(double));
+      double* const ptr = &ao_vgl[ipoint*5*ao_num];
+      for (size_t k=0 ; k<5*ao_num ; ++k) {
+        ptr[k] = 0.;
+      }
+
+//      memset(&ao_vgl[ipoint*ao_num*5], 0, 5*ao_num*sizeof(double));
 
       const double e_coord[3]  __attribute__((aligned(64))) =
         { coord[ipoint],