diff --git a/opm/core/GridManager.cpp b/opm/core/GridManager.cpp
index d286e504..528e2e12 100644
--- a/opm/core/GridManager.cpp
+++ b/opm/core/GridManager.cpp
@@ -97,6 +97,20 @@ namespace Opm
 
 
 
+    /// Construct a grid from an input file.
+    /// The file format used is currently undocumented,
+    /// and is therefore only suited for internal use.
+    GridManager::GridManager(const std::string& input_filename)
+    {
+        ug_ = read_grid(input_filename.c_str());
+        if (!ug_) {
+            THROW("Failed to read grid from file " << input_filename);
+        }
+    }
+
+
+
+
     /// Destructor.
     GridManager::~GridManager()
     {
diff --git a/opm/core/GridManager.hpp b/opm/core/GridManager.hpp
index 26e335f2..36846f2c 100644
--- a/opm/core/GridManager.hpp
+++ b/opm/core/GridManager.hpp
@@ -20,6 +20,7 @@
 #ifndef OPM_GRIDMANAGER_HEADER_INCLUDED
 #define OPM_GRIDMANAGER_HEADER_INCLUDED
 
+#include <string>
 
 struct UnstructuredGrid;
 
@@ -53,6 +54,11 @@ namespace Opm
         GridManager(int nx, int ny, int nz,
                     double dx, double dy, double dz);
 
+        /// Construct a grid from an input file.
+        /// The file format used is currently undocumented,
+        /// and is therefore only suited for internal use.
+        GridManager(const std::string& input_filename);
+
         /// Destructor.
         ~GridManager();