diff --git a/include/poet/DHT_Wrapper.hpp b/include/poet/DHT_Wrapper.hpp
index a9959e2f5..4077d88d6 100644
--- a/include/poet/DHT_Wrapper.hpp
+++ b/include/poet/DHT_Wrapper.hpp
@@ -106,7 +106,7 @@ public:
    * @param dt Current timestep of simulation
    */
   auto checkDHT(int length, std::vector<bool> &out_result_index,
-                double *work_package, double dt)
+                const std::vector<double> &work_package, double dt)
       -> std::vector<std::vector<double>>;
 
   /**
@@ -125,8 +125,9 @@ public:
    * outputs of the PHREEQC simulation
    * @param dt Current timestep of simulation
    */
-  void fillDHT(int length, std::vector<bool> &result_index,
-               double *work_package, double *results, double dt);
+  void fillDHT(int length, const std::vector<bool> &result_index,
+               const std::vector<double> &work_package,
+               const std::vector<double> &results, double dt);
 
   /**
    * @brief Dump current DHT state into file.
diff --git a/src/ChemWorker.cpp b/src/ChemWorker.cpp
index 51726ac90..b3b2852ae 100644
--- a/src/ChemWorker.cpp
+++ b/src/ChemWorker.cpp
@@ -199,8 +199,8 @@ void ChemWorker::doWork(MPI_Status &probe_status) {
     dht_get_start = MPI_Wtime();
     vecDHTKeys = this->phreeqc_rm->ReplaceTotalsByPotentials(
         vecCurrWP, local_work_package_size);
-    vecDHTResults = dht->checkDHT(local_work_package_size, vecNeedPhreeqc,
-                                  vecDHTKeys.data(), dt);
+    vecDHTResults =
+        dht->checkDHT(local_work_package_size, vecNeedPhreeqc, vecDHTKeys, dt);
     dht_get_end = MPI_Wtime();
 
     uint32_t iMappingIndex = 0;
@@ -234,8 +234,8 @@ void ChemWorker::doWork(MPI_Status &probe_status) {
   if (dht_enabled) {
     /* write results to DHT */
     dht_fill_start = MPI_Wtime();
-    dht->fillDHT(local_work_package_size, vecNeedPhreeqc, vecDHTKeys.data(),
-                 vecCurrWP.data(), dt);
+    dht->fillDHT(local_work_package_size, vecNeedPhreeqc, vecDHTKeys, vecCurrWP,
+                 dt);
     dht_fill_end = MPI_Wtime();
 
     timing[1] += dht_get_end - dht_get_start;
diff --git a/src/DHT_Wrapper.cpp b/src/DHT_Wrapper.cpp
index d053a28fe..02e503911 100644
--- a/src/DHT_Wrapper.cpp
+++ b/src/DHT_Wrapper.cpp
@@ -76,7 +76,7 @@ DHT_Wrapper::~DHT_Wrapper() {
 }
 
 auto DHT_Wrapper::checkDHT(int length, std::vector<bool> &out_result_index,
-                           double *work_package, double dt)
+                           const std::vector<double> &work_package, double dt)
     -> std::vector<std::vector<double>> {
   void *key;
   int res;
@@ -114,8 +114,9 @@ auto DHT_Wrapper::checkDHT(int length, std::vector<bool> &out_result_index,
   return data;
 }
 
-void DHT_Wrapper::fillDHT(int length, std::vector<bool> &result_index,
-                          double *work_package, double *results, double dt) {
+void DHT_Wrapper::fillDHT(int length, const std::vector<bool> &result_index,
+                          const std::vector<double> &work_package,
+                          const std::vector<double> &results, double dt) {
   void *key;
   void *data;
   int res;