Index: Ringtoets/HydraRing/src/Ringtoets.HydraRing.Calculation/Activities/HydraRingActivityBase.cs
===================================================================
diff -u -r64d60335b1deab4bafd37f78f3514660cc4afb27 -r3e7ad932cae845b4fc9ef970b429bf967066eacb
--- Ringtoets/HydraRing/src/Ringtoets.HydraRing.Calculation/Activities/HydraRingActivityBase.cs	(.../HydraRingActivityBase.cs)	(revision 64d60335b1deab4bafd37f78f3514660cc4afb27)
+++ Ringtoets/HydraRing/src/Ringtoets.HydraRing.Calculation/Activities/HydraRingActivityBase.cs	(.../HydraRingActivityBase.cs)	(revision 3e7ad932cae845b4fc9ef970b429bf967066eacb)
@@ -64,9 +64,6 @@
         /// then <c>false</c> is returned and the problems are logged.
         /// </summary>
         /// <returns><c>true</c> if no validation problems were found, <c>false</c> otherwise.</returns>
-        protected virtual bool Validate()
-        {
-            return true;
-        }
+        protected abstract bool Validate();
     }
 }
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