diff --git a/opm/core/fluid/BlackoilPropertiesBasic.cpp b/opm/core/fluid/BlackoilPropertiesBasic.cpp
index 4b8dbef29..25b520d61 100644
--- a/opm/core/fluid/BlackoilPropertiesBasic.cpp
+++ b/opm/core/fluid/BlackoilPropertiesBasic.cpp
@@ -168,6 +168,14 @@ namespace Opm
         }
     }
 
+    /// Densities of stock components at surface conditions.
+    /// \return Array of P density values.
+    const double* BlackoilPropertiesBasic::surfaceDensity() const
+    {
+        return pvt_.surfaceDensities();
+    }
+
+
     /// \param[in]  n      Number of data points.
     /// \param[in]  s      Array of nP saturation values.
     /// \param[in]  cells  Array of n cell indices to be associated with the s values.
diff --git a/opm/core/fluid/BlackoilPropertiesBasic.hpp b/opm/core/fluid/BlackoilPropertiesBasic.hpp
index 24a01a1c0..76dc4bd4e 100644
--- a/opm/core/fluid/BlackoilPropertiesBasic.hpp
+++ b/opm/core/fluid/BlackoilPropertiesBasic.hpp
@@ -104,6 +104,7 @@ namespace Opm
                             double* dAdp) const;
 
 
+        /// Densities of stock components at reservoir conditions.
         /// \param[in]  n      Number of data points.
         /// \param[in]  A      Array of nP^2 values, where the P^2 values for a cell give the
         ///                    matrix A = RB^{-1} which relates z to u by z = Au. The matrices
@@ -114,6 +115,10 @@ namespace Opm
                              const double* A,
                              double* rho) const;
 
+        /// Densities of stock components at surface conditions.
+        /// \return Array of P density values.
+        virtual const double* surfaceDensity() const;
+
         /// \param[in]  n      Number of data points.
         /// \param[in]  s      Array of nP saturation values.
         /// \param[in]  cells  Array of n cell indices to be associated with the s values.
diff --git a/opm/core/fluid/BlackoilPropertiesFromDeck.cpp b/opm/core/fluid/BlackoilPropertiesFromDeck.cpp
index f582d4458..5aeb58fcc 100644
--- a/opm/core/fluid/BlackoilPropertiesFromDeck.cpp
+++ b/opm/core/fluid/BlackoilPropertiesFromDeck.cpp
@@ -213,6 +213,13 @@ namespace Opm
         }
     }
 
+    /// Densities of stock components at surface conditions.
+    /// \return Array of P density values.
+    const double* BlackoilPropertiesFromDeck::surfaceDensity() const
+    {
+        return pvt_.surfaceDensities();
+    }
+
     /// \param[in]  n      Number of data points.
     /// \param[in]  s      Array of nP saturation values.
     /// \param[in]  cells  Array of n cell indices to be associated with the s values.
diff --git a/opm/core/fluid/BlackoilPropertiesFromDeck.hpp b/opm/core/fluid/BlackoilPropertiesFromDeck.hpp
index a9b867960..a6408e066 100644
--- a/opm/core/fluid/BlackoilPropertiesFromDeck.hpp
+++ b/opm/core/fluid/BlackoilPropertiesFromDeck.hpp
@@ -100,6 +100,7 @@ namespace Opm
                             double* dAdp) const;
 
 
+        /// Densities of stock components at reservoir conditions.
         /// \param[in]  n      Number of data points.
         /// \param[in]  A      Array of nP^2 values, where the P^2 values for a cell give the
         ///                    matrix A = RB^{-1} which relates z to u by z = Au. The matrices
@@ -110,6 +111,10 @@ namespace Opm
                              const double* A,
                              double* rho) const;
 
+        /// Densities of stock components at surface conditions.
+        /// \return Array of P density values.
+        virtual const double* surfaceDensity() const;
+
         /// \param[in]  n      Number of data points.
         /// \param[in]  s      Array of nP saturation values.
         /// \param[in]  cells  Array of n cell indices to be associated with the s values.
diff --git a/opm/core/fluid/BlackoilPropertiesInterface.hpp b/opm/core/fluid/BlackoilPropertiesInterface.hpp
index d3ea428c7..393036a27 100644
--- a/opm/core/fluid/BlackoilPropertiesInterface.hpp
+++ b/opm/core/fluid/BlackoilPropertiesInterface.hpp
@@ -91,6 +91,7 @@ namespace Opm
                             double* dAdp) const = 0;
 
 
+        /// Densities of stock components at reservoir conditions.
         /// \param[in]  n      Number of data points.
         /// \param[in]  A      Array of nP^2 values, where the P^2 values for a cell give the
         ///                    matrix A = RB^{-1} which relates z to u by z = Au. The matrices
@@ -101,6 +102,10 @@ namespace Opm
                              const double* A,
                              double* rho) const = 0;
 
+        /// Densities of stock components at surface conditions.
+        /// \return Array of P density values.
+        virtual const double* surfaceDensity() const = 0;
+
         /// \param[in]  n      Number of data points.
         /// \param[in]  s      Array of nP saturation values.
         /// \param[in]  cells  Array of n cell indices to be associated with the s values.