diff --git a/ebos/eclgenericthresholdpressure.cc b/ebos/eclgenericthresholdpressure.cc
index 2079846c5..cd65d9f8c 100644
--- a/ebos/eclgenericthresholdpressure.cc
+++ b/ebos/eclgenericthresholdpressure.cc
@@ -220,6 +220,34 @@ configureThpresft_()
     }
 }
 
+template<class Grid, class GridView, class ElementMapper, class Scalar>
+std::vector<Scalar>
+EclGenericThresholdPressure<Grid,GridView,ElementMapper,Scalar>::
+getRestartVector() const
+{
+    if (!enableThresholdPressure_)
+        return {};
+
+    std::vector<Scalar> result(numEquilRegions_ * numEquilRegions_, 0.0);
+    const auto& simConfig = eclState_.getSimulationConfig();
+    const auto& thpres = simConfig.getThresholdPressure();
+
+    std::size_t idx = 0;
+    for (unsigned j = 1; j <= numEquilRegions_; ++j) {
+        for (unsigned i = 1; i <= numEquilRegions_; ++i, ++idx) {
+            if (thpres.hasRegionBarrier(i, j)) {
+                if (thpres.hasThresholdPressure(i, j)) {
+                    result[idx] = thpres.getThresholdPressure(i, j);
+                } else {
+                    result[idx] = this->thpresDefault_[idx];
+                }
+            }
+        }
+    }
+
+    return result;
+}
+
 #if HAVE_DUNE_FEM
 template class EclGenericThresholdPressure<Dune::CpGrid,
                                            Dune::GridView<Dune::Fem::GridPart2GridViewTraits<Dune::Fem::AdaptiveLeafGridPart<Dune::CpGrid, Dune::PartitionIteratorType(4), false>>>,
diff --git a/ebos/eclgenericthresholdpressure.hh b/ebos/eclgenericthresholdpressure.hh
index 404d932b3..750edc387 100644
--- a/ebos/eclgenericthresholdpressure.hh
+++ b/ebos/eclgenericthresholdpressure.hh
@@ -72,6 +72,10 @@ public:
     void setFromRestart(const std::vector<Scalar>& values)
     { thpres_ = values; }
 
+    //! \brief Returns a fully expanded vector for restart file writing.
+    //! \details Returns the union of explicitly configured entries and defaulted values.
+    std::vector<Scalar> getRestartVector() const;
+
 protected:
     /*!
      * \brief Actually compute the threshold pressures over a face as a pre-compute step.
@@ -90,7 +94,7 @@ protected:
     const EclipseState& eclState_;
     std::vector<Scalar> thpresDefault_;
     std::vector<Scalar> thpres_;
-    unsigned numEquilRegions_;
+    unsigned numEquilRegions_{};
     std::vector<unsigned char> elemEquilRegion_;
 
     // threshold pressure accross faults. EXPERIMENTAL!
diff --git a/ebos/eclwriter.hh b/ebos/eclwriter.hh
index 04978a209..14a18dfb0 100644
--- a/ebos/eclwriter.hh
+++ b/ebos/eclwriter.hh
@@ -377,7 +377,7 @@ public:
                                 this->actionState(),
                                 this->udqState(),
                                 this->summaryState(),
-                                simulator_.problem().thresholdPressure().data(),
+                                simulator_.problem().thresholdPressure().getRestartVector(),
                                 curTime, nextStepSize,
                                 EWOMS_GET_PARAM(TypeTag, bool, EclOutputDoublePrecision),
                                 isFlowsn,