diff --git a/src/test/kotlin/no/liflig/documentstore/repository/MigrationTest.kt b/src/test/kotlin/no/liflig/documentstore/repository/MigrationTest.kt
index d90b5ce..5f06903 100644
--- a/src/test/kotlin/no/liflig/documentstore/repository/MigrationTest.kt
+++ b/src/test/kotlin/no/liflig/documentstore/repository/MigrationTest.kt
@@ -1,17 +1,27 @@
+@file:UseSerializers(InstantSerializer::class)
+
 package no.liflig.documentstore.repository
 
 import java.text.DecimalFormat
+import java.time.Instant
 import kotlin.test.assertEquals
 import kotlin.test.assertFailsWith
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.UseSerializers
+import no.liflig.documentstore.entity.Entity
 import no.liflig.documentstore.testutils.exampleRepo
 import no.liflig.documentstore.testutils.exampleRepoPostMigration
 import no.liflig.documentstore.testutils.exampleRepoPreMigration
 import no.liflig.documentstore.testutils.examples.ExampleEntity
+import no.liflig.documentstore.testutils.examples.ExampleId
+import no.liflig.documentstore.testutils.examples.InstantSerializer
+import no.liflig.documentstore.testutils.examples.KotlinSerialization
 import no.liflig.documentstore.testutils.jdbi
+import org.jdbi.v3.core.Jdbi
 import org.junit.jupiter.api.AfterEach
+import org.junit.jupiter.api.Disabled
 import org.junit.jupiter.api.Test
 
-@OptIn(RepositoryMigrationApi::class)
 class MigrationTest {
   @AfterEach
   fun clear() {
@@ -70,4 +80,118 @@ class MigrationTest {
       assertEquals("Original", entity.item.text)
     }
   }
+
+  // Disabled for automatic tests, since this is a heavy test that we don't want to run in CI
+  @Disabled
+  @Test
+  fun `load-test migration`() {
+    val existingEntities =
+        (0L until 500_000L)
+            .asSequence()
+            .map { number ->
+              // Create unique values for each field, to make the data more realistic
+              LargeEntityPreMigration(
+                  field1 = TwoStrings("field1-${number}", "field1-${number +1}"),
+                  field2 = StringAndInstant("field2-${number}", Instant.now()),
+                  field3 =
+                      EnumAndInstant(ExampleEnum.valueOf("VALUE_${number % 4}"), Instant.now()),
+                  field4 = listOf("field4-${number}", "field4-${number + 1}"),
+                  field5 = number,
+                  field6 = number % 2 == 0L,
+                  field7 = "field7-${number}",
+                  field8 = "field8-${number}",
+              )
+            }
+            .asIterable()
+    largeEntityRepoPreMigration.batchCreate(existingEntities)
+
+    // Give some time after batchCreate, to more accurately simulate migration after creation
+    Thread.sleep(1000)
+
+    largeEntityRepoPostMigration.migrate()
+
+    println("Successfully migrated!")
+  }
+}
+
+private val largeEntityRepoPreMigration: LargeEntityRepoPreMigration by lazy {
+  LargeEntityRepoPreMigration(jdbi)
+}
+
+private class LargeEntityRepoPreMigration(jdbi: Jdbi) :
+    RepositoryJdbi<ExampleId, LargeEntityPreMigration>(
+        jdbi,
+        // We can re-use the migration table here, since we truncate it between every test
+        tableName = "example_for_migration",
+        serializationAdapter = KotlinSerialization(LargeEntityPreMigration.serializer()),
+    )
+
+private val largeEntityRepoPostMigration: LargeEntityRepoPostMigration by lazy {
+  LargeEntityRepoPostMigration(jdbi)
+}
+
+private class LargeEntityRepoPostMigration(jdbi: Jdbi) :
+    RepositoryJdbi<ExampleId, LargeEntityPostMigration>(
+        jdbi,
+        // We can re-use the migration table here, since we truncate it between every test
+        tableName = "example_for_migration",
+        serializationAdapter = KotlinSerialization(LargeEntityPostMigration.serializer()),
+    )
+
+/**
+ * An example of a larger entity than [ExampleEntity], for load-testing the repository migration API
+ * with more realistic data.
+ */
+@Serializable
+private data class LargeEntityPreMigration(
+    override val id: ExampleId = ExampleId(),
+    val field1: TwoStrings,
+    val field2: StringAndInstant,
+    val field3: EnumAndInstant,
+    val field4: List<String>,
+    val field5: Long,
+    val field6: Boolean,
+    val field7: String,
+    val field8: String,
+) : Entity<ExampleId>
+
+@Serializable
+private data class LargeEntityPostMigration(
+    override val id: ExampleId = ExampleId(),
+    val field1: TwoStrings,
+    val field2: StringAndInstant,
+    val field3: EnumAndInstant,
+    val field4: List<String>,
+    val field5: Long,
+    val field6: Boolean,
+    val field7: String,
+    val field8: String,
+    val field9: String? = null,
+    val field10: String = field7,
+) : Entity<ExampleId>
+
+@Serializable
+private data class TwoStrings(
+    val field1: String,
+    val field2: String,
+)
+
+@Serializable
+private data class StringAndInstant(
+    val field1: String,
+    val field2: Instant,
+)
+
+@Serializable
+private data class EnumAndInstant(
+    val field1: ExampleEnum,
+    val field2: Instant,
+)
+
+@Serializable
+enum class ExampleEnum {
+  VALUE_0,
+  VALUE_1,
+  VALUE_2,
+  VALUE_3,
 }