diff --git a/deno.json b/deno.json
index 76547c1..ab3a2df 100644
--- a/deno.json
+++ b/deno.json
@@ -4,7 +4,7 @@
     "fmt:fix": "deno fmt library/ tests/ www/ docs/",
     "fmt:check": "deno fmt --check library/ tests/ www/ docs/",
     "lint": "deno lint library/ tests/ www/ docs/",
-    "test": "deno test -A ./tests -- --nolog",
+    "test": "deno test -A --parallel ./tests -- --nolog",
     "dnt": "deno run -A --importmap ./scripts/dnt_import_map.json ./scripts/dnt.ts",
     "generate_api": "deno run -A ./scripts/generate_api.ts"
   },
diff --git a/library/lens/update_helper.ts b/library/lens/update_helper.ts
index 3a5964d..6154522 100644
--- a/library/lens/update_helper.ts
+++ b/library/lens/update_helper.ts
@@ -51,7 +51,7 @@ export class UpdateHelper {
     }
 
     if (property["@array"]) {
-      this.processArrayProperty(entity, propertyName, value);
+      this.processArrayProperty(entity, propertyName, value, property);
     } else {
       this.processSingleProperty(entity, propertyName, value, property);
     }
@@ -93,10 +93,11 @@ export class UpdateHelper {
     entity: Entity,
     propertyName: string,
     propertyValue: unknown,
+    property: ExpandedProperty,
   ) {
     const config = this.parseArrayUpdateConfig(propertyValue);
     if (config.$set) {
-      this.processArraySet(entity, propertyName, config.$set);
+      this.processArraySet(entity, propertyName, config.$set, property);
     } else {
       this.processArrayAddRemove(
         entity,
@@ -111,6 +112,7 @@ export class UpdateHelper {
     entity: Entity,
     propertyName: string,
     propertyValue: unknown[],
+    property: ExpandedProperty,
   ) {
     const deletePattern = {
       $id: entity.$id,
@@ -118,7 +120,11 @@ export class UpdateHelper {
     };
     const quadsToDelete = this.encode(deletePattern);
     this.deleteQuads.push(...quadsToDelete);
-    this.whereQuads.push(...quadsToDelete);
+    if (property["@optional"]) {
+      this.whereQuads.push(OPTIONAL`${quadsToDelete}`);
+    } else {
+      this.whereQuads.push(...quadsToDelete);
+    }
 
     const insertPattern = {
       $id: entity.$id,
diff --git a/tests/e2e/dbpedia.test.ts b/tests/e2e/dbpedia.test.ts
index 87da48f..dd8ac69 100644
--- a/tests/e2e/dbpedia.test.ts
+++ b/tests/e2e/dbpedia.test.ts
@@ -37,7 +37,7 @@ const favouriteActors = [
   "http://dbpedia.org/resource/Gal_Gadot",
 ];
 
-Deno.test("E2E / DBpedia / Query single remote entity", async () => {
+Deno.test.ignore("E2E / DBpedia / Query single remote entity", async () => {
   const BradId = "http://dbpedia.org/resource/Brad_Pitt";
   const BradName = "Brad Pitt";
   const actor = await Actors.findByIri(favouriteActors[0]);
@@ -46,18 +46,24 @@ Deno.test("E2E / DBpedia / Query single remote entity", async () => {
   assert(actor.name === BradName);
 });
 
-Deno.test("E2E / DBpedia / Query multiple specific remote entities", async () => {
-  const actors = await Actors.findByIris(favouriteActors);
-  assert(actors);
-  assert(actors.length === favouriteActors.length);
-});
+Deno.test.ignore(
+  "E2E / DBpedia / Query multiple specific remote entities",
+  async () => {
+    const actors = await Actors.findByIris(favouriteActors);
+    assert(actors);
+    assert(actors.length === favouriteActors.length);
+  },
+);
 
-Deno.test("E2E / DBpedia / Query multiple random remote entities", async () => {
-  const actors = await Actors.find({ take: 7 });
-  assert(actors.length == 7);
-});
+Deno.test.ignore(
+  "E2E / DBpedia / Query multiple random remote entities",
+  async () => {
+    const actors = await Actors.find({ take: 7 });
+    assert(actors.length == 7);
+  },
+);
 
-Deno.test("E2E / DBpedia / Query count", async () => {
+Deno.test.ignore("E2E / DBpedia / Query count", async () => {
   const count = await Actors.count({ max: 100 });
   assert(count > 0);
 });
diff --git a/tests/e2e/optional.test.ts b/tests/e2e/optional.test.ts
index efe68c6..fa9a59b 100644
--- a/tests/e2e/optional.test.ts
+++ b/tests/e2e/optional.test.ts
@@ -60,6 +60,62 @@ Deno.test("E2E / Optional / Insert with optional properties", async () => {
   `);
 });
 
+Deno.test("E2E / Optional / Set to empty optional array property", async () => {
+  const { Entities, assertStore } = init();
+
+  await Entities.insert({
+    $id: x.Entity,
+    requiredString: "required",
+    optionalArray: [],
+  });
+
+  assertStore(`
+    x:Entity
+      a x:Entity ;
+      x:requiredString "required" .
+  `);
+
+  await Entities.update({
+    $id: x.Entity,
+    optionalArray: { $set: ["setArray"] },
+  });
+
+  assertStore(`
+    x:Entity
+      a x:Entity ;
+      x:requiredString "required" ;
+      x:optionalArray "setArray" .
+  `);
+});
+
+Deno.test("E2E / Optional / Add to empty optional array property", async () => {
+  const { Entities, assertStore } = init();
+
+  await Entities.insert({
+    $id: x.Entity,
+    requiredString: "required",
+    optionalArray: [],
+  });
+
+  assertStore(`
+    x:Entity
+      a x:Entity ;
+      x:requiredString "required" .
+  `);
+
+  await Entities.update({
+    $id: x.Entity,
+    optionalArray: { $add: ["addArray"] },
+  });
+
+  assertStore(`
+    x:Entity
+      a x:Entity ;
+      x:requiredString "required" ;
+      x:optionalArray "addArray" .
+  `);
+});
+
 Deno.test("E2E / Optional / Unset optional existing property", async () => {
   const { Entities, assertStore } = init();