diff --git a/opm/output/OutputWriter.hpp b/opm/output/OutputWriter.hpp
index b4d72b3ad..06995d822 100644
--- a/opm/output/OutputWriter.hpp
+++ b/opm/output/OutputWriter.hpp
@@ -75,7 +75,7 @@ public:
      * This routine should be called before the first timestep (i.e. when
      * timer.currentStepNum () == 0)
      */
-    virtual void writeInit( const NNC& nnc = NNC() ) = 0;
+    virtual void writeInit( const NNC& nnc ) = 0;
 
     /*!
      * \brief Write a blackoil reservoir state to disk for later inspection with
diff --git a/opm/output/eclipse/EclipseWriter.hpp b/opm/output/eclipse/EclipseWriter.hpp
index e69ee0798..546e2b04e 100644
--- a/opm/output/eclipse/EclipseWriter.hpp
+++ b/opm/output/eclipse/EclipseWriter.hpp
@@ -55,7 +55,7 @@ public:
      *
      * If NNC is given, writes TRANNNC keyword.
      */
-    void writeInit( const NNC& nnc = NNC() );
+    void writeInit( const NNC& nnc );
 
     /*!
      * \brief Write a reservoir state and summary information to disk.
diff --git a/tests/test_EclipseWriter.cpp b/tests/test_EclipseWriter.cpp
index bf26b9f27..d4f9d545c 100644
--- a/tests/test_EclipseWriter.cpp
+++ b/tests/test_EclipseWriter.cpp
@@ -266,7 +266,7 @@ BOOST_AUTO_TEST_CASE(EclipseWriterIntegration)
 
         auto start_time = util_make_datetime( 0, 0, 0, 10, 10, 2008 );
         auto first_step = util_make_datetime( 0, 0, 0, 10, 11, 2008 );
-        eclWriter.writeInit();
+        eclWriter.writeInit( NNC() );
 
         data::Wells wells;
 
diff --git a/tests/test_RFT.cpp b/tests/test_RFT.cpp
index a870d2d60..356f315a7 100755
--- a/tests/test_RFT.cpp
+++ b/tests/test_RFT.cpp
@@ -125,7 +125,7 @@ BOOST_AUTO_TEST_CASE(test_RFT) {
         time_t start_time = eclipseState->getSchedule()->posixStartTime();
         /* step time read from deck and hard-coded here */
         time_t step_time = util_make_datetime( 0, 0, 0, 10, 10, 2008 );
-        eclipseWriter.writeInit();
+        eclipseWriter.writeInit( NNC() );
 
         Opm::data::Wells wells {
             { { "OP_1", { {}, 1.0, 1.1, {} } },
diff --git a/tests/test_Restart.cpp b/tests/test_Restart.cpp
index 0c4871aed..d11d15050 100644
--- a/tests/test_Restart.cpp
+++ b/tests/test_Restart.cpp
@@ -232,7 +232,7 @@ first_sim(test_work_area_type * test_area) {
     EclipseWriter eclWriter( eclipseState, num_cells, nullptr );
     auto start_time = util_make_datetime( 0, 0, 0, 1, 11, 1979 );
     auto first_step = util_make_datetime( 0, 0, 0, 10, 10, 2008 );
-    eclWriter.writeInit();
+    eclWriter.writeInit( NNC() );
 
     auto sol = mkSolution( num_cells );
     auto wells = mkWells();
diff --git a/tests/test_writenumwells.cpp b/tests/test_writenumwells.cpp
index 942a1e1d8..9aca6b14f 100644
--- a/tests/test_writenumwells.cpp
+++ b/tests/test_writenumwells.cpp
@@ -141,7 +141,7 @@ BOOST_AUTO_TEST_CASE(EclipseWriteRestartWellInfo) {
     const auto num_cells = eclipseState->getInputGrid()->getCartesianSize();
     EclipseWriter eclipseWriter( eclipseState, num_cells, nullptr );
 
-    eclipseWriter.writeInit();
+    eclipseWriter.writeInit( NNC() );
 
     int countTimeStep = eclipseState->getSchedule()->getTimeMap()->numTimesteps();