diff --git a/lib/Service/ExampleSet/ExampleSetPrerequisites.php b/lib/Service/ExampleSet/ExampleSetPrerequisites.php
index c691af5ebb..255268a712 100644
--- a/lib/Service/ExampleSet/ExampleSetPrerequisites.php
+++ b/lib/Service/ExampleSet/ExampleSetPrerequisites.php
@@ -103,8 +103,8 @@ public function context(array $plan, DateTimeImmutable $today): array {
 	}//end context()
 
 	/**
-	 * Import every required register that is not on the instance, or that this set imported and removed the data of,
-	 * and record the import.
+	 * Import every required register that is not on the instance, that this set imported and removed the data of, or
+	 * whose descriptor ships a newer version than the instance holds, and record the import.
 	 *
 	 * @param array<string, mixed> $plan   The plan.
 	 * @param array<string, mixed> $record The record; gains the imports.
@@ -120,11 +120,14 @@ private function ensureRegisters(array $plan, array &$record): array {
 			$result['outcome'][$slug] = 'kept';
 			// A register this set imported whose import was removed again is on the instance without its data.
 			$dataRemoved = (array_key_exists($slug, $record['registers']) === true && $record['registers'][$slug] === []);
-			if ($this->registers->exists(slug: $slug) === true && $dataRemoved === false) {
+			$mock        = (($required['mock'] ?? false) === true);
+			if ($this->registers->exists(slug: $slug) === true && $dataRemoved === false
+				&& $this->registers->isBehind(slug: $slug, mock: $mock) === false
+			) {
 				continue;
 			}
 
-			$import = match (($required['mock'] ?? false) === true) {
+			$import = match ($mock) {
 				true  => $this->registers->importMock(slug: $slug),
 				false => $this->registers->import(slug: $slug),
 			};
diff --git a/lib/Service/ExampleSet/ExampleSetRegisters.php b/lib/Service/ExampleSet/ExampleSetRegisters.php
index 9a24e10304..74753177c2 100644
--- a/lib/Service/ExampleSet/ExampleSetRegisters.php
+++ b/lib/Service/ExampleSet/ExampleSetRegisters.php
@@ -125,6 +125,28 @@ public function importMock(string $slug): array {
 		);
 	}//end importMock()
 
+	/**
+	 * Whether the instance holds an older version of the register than
+	 * OpenRegister's descriptor ships, so the set imports it again. A
+	 * descriptor that cannot be read counts as not behind.
+	 *
+	 * @param string $slug The register slug.
+	 * @param bool   $mock True when the set requires the mock descriptor.
+	 *
+	 * @return bool
+	 *
+	 * @phpstan-impure It reads the instance, which an import changes.
+	 *
+	 * @spec openspec/changes/example-sets/specs/example-sets/spec.md#requirement-a-set-imports-the-openregister-registers-it-requires-req-exs-009
+	 */
+	public function isBehind(string $slug, bool $mock): bool {
+		try {
+			return $this->container->get(RegisterDescriptorService::class)->isBehind(appId: self::APP, slug: $slug, mock: $mock);
+		} catch (Throwable) {
+			return false;
+		}
+	}//end isBehind()
+
 	/**
 	 * Run one descriptor import and return why it failed and the import job it reports.
 	 *
diff --git a/lib/Service/RegisterDescriptorService.php b/lib/Service/RegisterDescriptorService.php
index d8671ec8b1..07037aaa24 100644
--- a/lib/Service/RegisterDescriptorService.php
+++ b/lib/Service/RegisterDescriptorService.php
@@ -475,6 +475,37 @@ public function reimportMock(string $appId, string $slug): array {
 		] + $job;
 	}//end reimportMock()
 
+	/**
+	 * Whether the instance holds an older version of a register than the
+	 * descriptor of the given kind (mock or real) ships.
+	 *
+	 * A register that is not on the instance, or that no descriptor of the
+	 * kind declares, is not behind: there is nothing to bring up to date.
+	 *
+	 * @param string $appId The app whose descriptors are read.
+	 * @param string $slug  The register slug.
+	 * @param bool   $mock  True for the mock descriptor, false for the real one.
+	 *
+	 * @return bool True when the shipped version is newer than the installed one.
+	 *
+	 * @spec openspec/changes/example-sets/specs/example-sets/spec.md#requirement-a-set-imports-the-openregister-registers-it-requires-req-exs-009
+	 */
+	public function isBehind(string $appId, string $slug, bool $mock): bool {
+		$descriptor = $this->descriptorFor(appId: $appId, slug: $slug, mock: $mock);
+		$installed  = ($this->installedRegisterVersions()[strtolower($slug)] ?? null);
+		if ($descriptor === null || $installed === null) {
+			return false;
+		}
+
+		foreach ($descriptor['registers'] as $declared => $register) {
+			if (strtolower((string)$declared) === strtolower($slug)) {
+				return version_compare((string)($register['version'] ?? '0.0.1'), $installed, '>');
+			}
+		}
+
+		return false;
+	}//end isBehind()
+
 	/**
 	 * Slug (lowercased) to version for every register that exists.
 	 *
diff --git a/lib/Settings/public_space_register.json b/lib/Settings/public_space_register.json
index 4805a9932e..68bcab902f 100644
--- a/lib/Settings/public_space_register.json
+++ b/lib/Settings/public_space_register.json
@@ -3,7 +3,7 @@
   "info": {
     "title": "Public Space Mock Register",
     "description": "Mock register of objects in public space (openbare ruimte): trees, street lights, play equipment, market pitches and road sections. Example data a case can link an object to; the Zuiddrecht example set imports it and fills it.",
-    "version": "1.0.0"
+    "version": "1.0.1"
   },
   "x-openregister": {
     "type": "mock",
@@ -16,6 +16,7 @@
     "registers": {
       "public-space": {
         "slug": "public-space",
+        "version": "1.0.1",
         "title": "Openbare ruimte",
         "description": "Objects in public space that the municipality manages and that cases are about: trees, street lights, play equipment, market pitches and road sections.",
         "schemas": [
@@ -32,7 +33,7 @@
       "tree": {
         "slug": "tree",
         "title": "Bomenregister",
-        "version": "1.0.0",
+        "version": "1.0.1",
         "summary": "A tree the municipality manages in public space.",
         "description": "A tree the municipality manages in public space.",
         "type": "object",
@@ -109,7 +110,7 @@
       "street-light": {
         "slug": "street-light",
         "title": "Openbare verlichting",
-        "version": "1.0.0",
+        "version": "1.0.1",
         "summary": "A street light or light mast the municipality manages.",
         "description": "A street light or light mast the municipality manages.",
         "type": "object",
@@ -175,7 +176,7 @@
       "play-equipment": {
         "slug": "play-equipment",
         "title": "Buitenruimte",
-        "version": "1.0.0",
+        "version": "1.0.1",
         "summary": "A piece of play equipment on a public playground.",
         "description": "A piece of play equipment on a public playground.",
         "type": "object",
@@ -322,7 +323,7 @@
       "road-section": {
         "slug": "road-section",
         "title": "Wegen en paden",
-        "version": "1.0.0",
+        "version": "1.0.1",
         "summary": "A road, cycle path or footpath section the municipality manages.",
         "description": "A road, cycle path or footpath section the municipality manages.",
         "type": "object",
diff --git a/tests/Unit/Service/Configuration/ImportHandlerSchemaVersioningTest.php b/tests/Unit/Service/Configuration/ImportHandlerSchemaVersioningTest.php
index 52a6ea2a1e..9b9fa03e99 100644
--- a/tests/Unit/Service/Configuration/ImportHandlerSchemaVersioningTest.php
+++ b/tests/Unit/Service/Configuration/ImportHandlerSchemaVersioningTest.php
@@ -257,6 +257,39 @@ public function testANewerVersionWithTheSameDefinitionRecordsNothing(): void {
 		$this->assertSame('1.0.1', $this->written['version']);
 	}//end testANewerVersionWithTheSameDefinitionRecordsNothing()
 
+	/**
+	 * An import at a higher version replaces a stored property's definition:
+	 * a location stored as `type: geo`, which no JSON Schema validator accepts,
+	 * becomes the shipped `{"type": "object", "format": "geo:point"}`.
+	 *
+	 * @return void
+	 */
+	public function testAHigherVersionReplacesAStoredProperty(): void {
+		$stored = $this->schema(
+			id: 31,
+			version: '1.0.0',
+			properties: ['name' => ['type' => 'string'], 'location' => ['type' => 'geo']],
+			required: []
+		);
+		$this->schemaMapper->method('find')->willReturn($stored);
+		$this->changelogMapper->method('createFromArray')->willReturn(new SchemaChangelog());
+
+		$this->handler->importSchema(
+			data: [
+				'slug' => 'case',
+				'title' => 'Case',
+				'version' => '1.0.1',
+				'properties' => ['name' => ['type' => 'string'], 'location' => ['type' => 'object', 'format' => 'geo:point']],
+				'required' => [],
+			],
+			slugsAndIdsMap: []
+		);
+
+		$location = $this->written['properties']['location'];
+		$this->assertSame(expected: ['object', 'geo:point'], actual: [$location['type'], $location['format']]);
+		$this->assertSame(expected: '1.0.1', actual: $this->written['version']);
+	}//end testAHigherVersionReplacesAStoredProperty()
+
 	/**
 	 * Pass 2 of a configuration import keeps the version Pass 1 bumped to (#4163).
 	 *
diff --git a/tests/Unit/Service/ExampleSet/ExampleSetRequirementsTest.php b/tests/Unit/Service/ExampleSet/ExampleSetRequirementsTest.php
index 19526edcf0..e81b0b603e 100644
--- a/tests/Unit/Service/ExampleSet/ExampleSetRequirementsTest.php
+++ b/tests/Unit/Service/ExampleSet/ExampleSetRequirementsTest.php
@@ -45,6 +45,26 @@
  * @uses \OCA\OpenRegister\Service\ExampleSet\ExampleSetViews
  */
 class ExampleSetRequirementsTest extends ExampleSetTestCase {
+	/**
+	 * A register already on the instance is imported again when the shipped
+	 * descriptor is a newer version, so a schema fixed in the descriptor
+	 * reaches an instance that installed the set before.
+	 *
+	 * @return void
+	 */
+	public function testARegisterBehindItsDescriptorIsImportedAgain(): void {
+		$this->store->offer(register: 'brp', schema: 'person');
+		$this->registers->present['brp']    = true;
+		$this->registers->importable['brp'] = true;
+		$this->registers->behind['brp']     = true;
+		$this->app(app: 'openregister', fragment: $this->castRequiringBrp());
+
+		$report = $this->installer->install(plan: $this->catalogue->gather(set: 'demo'), today: $this->today());
+
+		$this->assertSame(expected: ['brp' => 'imported'], actual: $report['registers']);
+		$this->assertSame(expected: 1, actual: $this->registers->imports);
+	}//end testARegisterBehindItsDescriptorIsImportedAgain()
+
 	/**
 	 * A cast file that requires the `brp` register and writes one person into it.
 	 *
diff --git a/tests/Unit/Service/ExampleSet/Fake/FakeExampleSetRegisters.php b/tests/Unit/Service/ExampleSet/Fake/FakeExampleSetRegisters.php
index e221af7f22..f447b252ba 100644
--- a/tests/Unit/Service/ExampleSet/Fake/FakeExampleSetRegisters.php
+++ b/tests/Unit/Service/ExampleSet/Fake/FakeExampleSetRegisters.php
@@ -44,6 +44,25 @@ class FakeExampleSetRegisters extends ExampleSetRegisters {
 	/** @var int Next job number. */
 	private int $next = 1;
 
+	/**
+	 * Slugs whose descriptor ships a newer version than the instance holds.
+	 *
+	 * @var array<string, true>
+	 */
+	public array $behind = [];
+
+	/**
+	 * Whether the slug is in `behind`.
+	 *
+	 * @param string $slug The register slug.
+	 * @param bool   $mock Whether the mock descriptor is meant.
+	 *
+	 * @return bool
+	 */
+	public function isBehind(string $slug, bool $mock): bool {
+		return isset($this->behind[$slug]);
+	}
+
 	/**
 	 * No container.
 	 */
diff --git a/tests/Unit/Service/RegisterDescriptorServiceTest.php b/tests/Unit/Service/RegisterDescriptorServiceTest.php
index 5e0ad652d7..a2b68af2f9 100644
--- a/tests/Unit/Service/RegisterDescriptorServiceTest.php
+++ b/tests/Unit/Service/RegisterDescriptorServiceTest.php
@@ -348,6 +348,24 @@ public function testReimportForcesPastTheVersionGate(): void {
 		$this->assertSame('imported', $result['outcome']);
 	}
 
+	/**
+	 * A register is behind when the descriptor of the asked kind ships a newer
+	 * version than the instance holds; same version, the other kind or a
+	 * register that is not there is not behind.
+	 *
+	 * @return void
+	 */
+	public function testARegisterIsBehindOnlyWhenItsDescriptorIsNewer(): void {
+		$this->writeDescriptor(file: 'a_mock_register.json', slug: 'flows', version: '1.0.1', type: 'mock');
+		$this->writeDescriptor(file: 'flows_register.json', slug: 'flows', version: '1.0.0');
+		$this->expectApp(appId: 'fixtureapp');
+		$this->registerMapper->method('findAll')->willReturn([$this->register(slug: 'flows', version: '1.0.0')]);
+
+		$this->assertTrue(condition: $this->service->isBehind(appId: 'fixtureapp', slug: 'flows', mock: true));
+		$this->assertFalse(condition: $this->service->isBehind(appId: 'fixtureapp', slug: 'flows', mock: false));
+		$this->assertFalse(condition: $this->service->isBehind(appId: 'fixtureapp', slug: 'other', mock: true));
+	}//end testARegisterIsBehindOnlyWhenItsDescriptorIsNewer()
+
 	/**
 	 * 🔴 A MOCK IMPORTS UNDER ITS OWN CONFIGURATION IDENTITY.
 	 *