Index: Ringtoets/Migration/src/Ringtoets.Migration.Core/EmbeddedResources/Migration_17.3_18.1.sql
===================================================================
diff -u -r0ffee99dd2d541d798adb7b0a09f6f6ef5371e34 -r5d48e0aa51c523ad324f95fab597df31511ed06e
--- Ringtoets/Migration/src/Ringtoets.Migration.Core/EmbeddedResources/Migration_17.3_18.1.sql	(.../Migration_17.3_18.1.sql)	(revision 0ffee99dd2d541d798adb7b0a09f6f6ef5371e34)
+++ Ringtoets/Migration/src/Ringtoets.Migration.Core/EmbeddedResources/Migration_17.3_18.1.sql	(.../Migration_17.3_18.1.sql)	(revision 5d48e0aa51c523ad324f95fab597df31511ed06e)
@@ -120,7 +120,29 @@
 	1
 FROM [SOURCEPROJECT].DuneErosionSectionResultEntity;
 INSERT INTO DuneLocationEntity SELECT * FROM [SOURCEPROJECT].DuneLocationEntity;
-INSERT INTO FailureMechanismEntity SELECT * FROM [SOURCEPROJECT].FailureMechanismEntity;
+INSERT INTO FailureMechanismEntity (
+	[FailureMechanismEntityId],
+	[AssessmentSectionEntityId],
+	[CalculationGroupEntityId],
+	[FailureMechanismType],
+	[IsRelevant],
+	[FailureMechanismSectionCollectionSourcePath],
+	[InputComments],
+	[OutputComments],
+	[NotRelevantComments])
+SELECT 
+	[FailureMechanismEntityId],
+	[AssessmentSectionEntityId],
+	[CalculationGroupEntityId],
+	[FailureMechanismType],
+	[IsRelevant],
+	CASE WHEN COUNT([FailureMechanismSectionEntityId]) THEN "" ELSE NULL END,
+	[InputComments],
+	[OutputComments],
+	[NotRelevantComments]
+FROM [SOURCEPROJECT].FailureMechanismEntity
+LEFT JOIN [SOURCEPROJECT].FailureMechanismSectionEntity USING (FailureMechanismEntityId)
+GROUP BY FailureMechanismEntityId;
 INSERT INTO FailureMechanismSectionEntity (
 	[FailureMechanismSectionEntityId],
 	[FailureMechanismEntityId],
Index: Ringtoets/Migration/test/Ringtoets.Migration.Core.Test/test-data/MigrationTestProject181.rtd
===================================================================
diff -u -r3f2f54a462f170710ac0b783c08da29584ed8041 -r5d48e0aa51c523ad324f95fab597df31511ed06e
Binary files differ
Index: Ringtoets/Migration/test/Ringtoets.Migration.Integration.Test/MigrationTo181IntegrationTest.cs
===================================================================
diff -u -r3f2f54a462f170710ac0b783c08da29584ed8041 -r5d48e0aa51c523ad324f95fab597df31511ed06e
--- Ringtoets/Migration/test/Ringtoets.Migration.Integration.Test/MigrationTo181IntegrationTest.cs	(.../MigrationTo181IntegrationTest.cs)	(revision 3f2f54a462f170710ac0b783c08da29584ed8041)
+++ Ringtoets/Migration/test/Ringtoets.Migration.Integration.Test/MigrationTo181IntegrationTest.cs	(.../MigrationTo181IntegrationTest.cs)	(revision 5d48e0aa51c523ad324f95fab597df31511ed06e)
@@ -84,6 +84,7 @@
                     AssertHydraulicBoundaryLocationsProperties(reader, sourceFilePath);
                     AssertHydraulicBoundaryLocationsOnAssessmentSection(reader, sourceFilePath);
                     AssertHydraulicBoundaryLocationsOnGrassCoverErosionOutwardsFailureMechanism(reader, sourceFilePath);
+                    AssertFailureMechanisms(reader, sourceFilePath);
 
                     AssertPipingSoilLayers(reader);
                     AssertStabilityStoneCoverFailureMechanism(reader);
@@ -488,6 +489,37 @@
             reader.AssertReturnedDataIsValid(validateForeignKeys);
         }
 
+        private static void AssertFailureMechanisms(MigratedDatabaseReader reader, string sourceFilePath)
+        {
+            const string validateFailureMechanismSectionsSourcePath =
+                "SELECT SUM([IsInvalid]) = 0 " +
+                "FROM (SELECT " +
+                "CASE WHEN " +
+                "COUNT([FailureMechanismSectionEntityId]) AND [FailureMechanismSectionCollectionSourcePath] IS NULL " +
+                "OR " +
+                "[FailureMechanismSectionCollectionSourcePath] IS NOT NULL AND NOT COUNT([FailureMechanismSectionEntityId]) " +
+                "THEN 1 ELSE 0 END AS [IsInvalid] " +
+                "FROM [FailureMechanismEntity] " +
+                "LEFT JOIN [FailureMechanismSectionEntity] USING([FailureMechanismEntityId]) " +
+                "GROUP BY [FailureMechanismEntityId]);";
+            reader.AssertReturnedDataIsValid(validateFailureMechanismSectionsSourcePath);
+
+            string validateFailureMechanisms =
+                $"ATTACH DATABASE \"{sourceFilePath}\" AS SOURCEPROJECT; " +
+                "SELECT COUNT() = (SELECT COUNT() FROM [SOURCEPROJECT].FailureMechanismEntity) " +
+                "FROM FailureMechanismEntity NEW " +
+                "JOIN [SOURCEPROJECT].FailureMechanismEntity OLD USING (FailureMechanismEntityId) " +
+                "WHERE NEW.AssessmentSectionEntityId = OLD.AssessmentSectionEntityId " +
+                "AND NEW.CalculationGroupEntityId IS OLD.CalculationGroupEntityId " +
+                "AND NEW.FailureMechanismType = OLD.FailureMechanismType " +
+                "AND NEW.IsRelevant = OLD.IsRelevant " +
+                "AND NEW.InputComments IS OLD.InputComments " +
+                "AND NEW.OutputComments IS OLD.OutputComments " +
+                "AND NEW.NotRelevantComments IS OLD.NotRelevantComments; " +
+                "DETACH DATABASE SOURCEPROJECT;";
+            reader.AssertReturnedDataIsValid(validateFailureMechanisms);
+        }
+
         private static void AssertPipingSoilLayers(MigratedDatabaseReader reader)
         {
             const string validateBelowPhreaticLevel =