diff --git a/opm/autodiff/BlackoilAquiferModel.hpp b/opm/autodiff/BlackoilAquiferModel.hpp
index c24a782b6..ac671ec67 100644
--- a/opm/autodiff/BlackoilAquiferModel.hpp
+++ b/opm/autodiff/BlackoilAquiferModel.hpp
@@ -44,50 +44,19 @@ namespace Opm {
         public:
             explicit BlackoilAquiferModel(Simulator& simulator);
 
-            void initialSolutionApplied()
-            {
-                for (auto aquifer = aquifers_.begin(); aquifer != aquifers_.end(); ++aquifer) {
-                    aquifer->initialSolutionApplied();
-                }
-            }
-
-            void beginEpisode()
-            { }
-
-            void beginTimeStep()
-            {
-                for (auto aquifer = aquifers_.begin(); aquifer != aquifers_.end(); ++aquifer) {
-                    aquifer->beginTimeStep();
-                }
-            }
-
-            void beginIteration()
-            { }
-
+            void initialSolutionApplied();
+            void beginEpisode();
+            void beginTimeStep();
+            void beginIteration();
             // add the water rate due to aquifers to the source term.
             template <class Context>
             void addToSource(RateVector& rates,
                              const Context& context,
                              unsigned spaceIdx,
-                             unsigned timeIdx) const
-            {
-                for (auto& aquifer: aquifers_) {
-                    aquifer.addToSource(rates, context, spaceIdx, timeIdx);
-                }
-            }
-
-            void endIteration()
-            { }
-
-            void endTimeStep()
-            {
-                for (auto aquifer = aquifers_.begin(); aquifer != aquifers_.end(); ++aquifer) {
-                    aquifer->endTimeStep();
-                }
-            }
-
-            void endEpisode()
-            { }
+                             unsigned timeIdx) const;
+            void endIteration();
+            void endTimeStep();
+            void endEpisode();
 
         protected:
             // ---------      Types      ---------
diff --git a/opm/autodiff/BlackoilAquiferModel_impl.hpp b/opm/autodiff/BlackoilAquiferModel_impl.hpp
index 3d9525c7d..2c5646746 100644
--- a/opm/autodiff/BlackoilAquiferModel_impl.hpp
+++ b/opm/autodiff/BlackoilAquiferModel_impl.hpp
@@ -9,6 +9,66 @@ namespace Opm {
         init();
     }
 
+    template<typename TypeTag>
+    void
+    BlackoilAquiferModel<TypeTag>::initialSolutionApplied()
+    {
+        for (auto aquifer = aquifers_.begin(); aquifer != aquifers_.end(); ++aquifer) {
+            aquifer->initialSolutionApplied();
+        }
+    }
+
+    template<typename TypeTag>
+    void
+    BlackoilAquiferModel<TypeTag>::beginEpisode()
+    { }
+
+    template<typename TypeTag>
+    void
+    BlackoilAquiferModel<TypeTag>::beginTimeStep()
+    {
+        for (auto aquifer = aquifers_.begin(); aquifer != aquifers_.end(); ++aquifer) {
+            aquifer->beginTimeStep();
+        }
+    }
+
+    template<typename TypeTag>
+    void
+    BlackoilAquiferModel<TypeTag>::beginIteration()
+    { }
+
+    template<typename TypeTag>
+    template <class Context>
+    void
+    BlackoilAquiferModel<TypeTag>::addToSource(RateVector& rates,
+                                               const Context& context,
+                                               unsigned spaceIdx,
+                                               unsigned timeIdx) const
+    {
+        for (auto& aquifer: aquifers_) {
+            aquifer.addToSource(rates, context, spaceIdx, timeIdx);
+        }
+    }
+
+    template<typename TypeTag>
+    void
+    BlackoilAquiferModel<TypeTag>::endIteration()
+    { }
+
+    template<typename TypeTag>
+    void
+    BlackoilAquiferModel<TypeTag>::endTimeStep()
+    {
+        for (auto aquifer = aquifers_.begin(); aquifer != aquifers_.end(); ++aquifer) {
+            aquifer->endTimeStep();
+        }
+    }
+
+    template<typename TypeTag>
+    void
+    BlackoilAquiferModel<TypeTag>::endEpisode()
+    { }
+
     // Initialize the aquifers in the deck
     template<typename TypeTag>
     void