diff --git a/backend/src/test/java/org/raddatz/familienarchiv/repository/MigrationIntegrationTest.java b/backend/src/test/java/org/raddatz/familienarchiv/repository/MigrationIntegrationTest.java
index 7fb3c406..db5b98a3 100644
--- a/backend/src/test/java/org/raddatz/familienarchiv/repository/MigrationIntegrationTest.java
+++ b/backend/src/test/java/org/raddatz/familienarchiv/repository/MigrationIntegrationTest.java
@@ -121,6 +121,53 @@ class MigrationIntegrationTest {
         assertThat(rows2).isEqualTo(1);
     }
 
+    // ─── V33: chk_annotation_bounds CHECK constraint ─────────────────────────
+
+    @Test
+    void v33_boundsCheckConstraint_rejectsXAboveOne() {
+        UUID docId = createDocument();
+
+        assertThatThrownBy(() ->
+                jdbc.update(
+                        """
+                        INSERT INTO document_annotations
+                            (id, document_id, page_number, x, y, width, height, color)
+                        VALUES (gen_random_uuid(), ?, 1, 1.5, 0.1, 0.3, 0.1, '#ff0000')
+                        """,
+                        docId)
+        ).isInstanceOf(DataIntegrityViolationException.class);
+    }
+
+    @Test
+    void v33_boundsCheckConstraint_rejectsHeightBelowMinimum() {
+        UUID docId = createDocument();
+
+        assertThatThrownBy(() ->
+                jdbc.update(
+                        """
+                        INSERT INTO document_annotations
+                            (id, document_id, page_number, x, y, width, height, color)
+                        VALUES (gen_random_uuid(), ?, 1, 0.1, 0.1, 0.3, 0.005, '#ff0000')
+                        """,
+                        docId)
+        ).isInstanceOf(DataIntegrityViolationException.class);
+    }
+
+    @Test
+    void v33_boundsCheckConstraint_acceptsValidAnnotation() {
+        UUID docId = createDocument();
+
+        int rows = jdbc.update(
+                """
+                INSERT INTO document_annotations
+                    (id, document_id, page_number, x, y, width, height, color)
+                VALUES (gen_random_uuid(), ?, 1, 0.1, 0.1, 0.3, 0.1, '#ff0000')
+                """,
+                docId);
+
+        assertThat(rows).isEqualTo(1);
+    }
+
     // ─── helpers ─────────────────────────────────────────────────────────────
 
     private UUID createDocument() {