diff --git a/src/index.cpp b/src/index.cpp
index fe589a45..fd000a3d 100644
--- a/src/index.cpp
+++ b/src/index.cpp
@@ -4456,6 +4456,10 @@ Option<uint32_t> Index::remove(const uint32_t seq_id, const nlohmann::json & doc
 
     if(!del_fields.empty()) {
         for(auto& the_field: del_fields) {
+            if(!document.contains(the_field.name)) {
+                // could be an optional field
+                continue;
+            }
             remove_field(seq_id, document, the_field.name);
         }
     } else {
diff --git a/test/collection_filtering_test.cpp b/test/collection_filtering_test.cpp
index 49b593fa..1e65258b 100644
--- a/test/collection_filtering_test.cpp
+++ b/test/collection_filtering_test.cpp
@@ -1890,6 +1890,37 @@ TEST_F(CollectionFilteringTest, NumericalRangeFilter) {
     collectionManager.drop_collection("coll1");
 }
 
+TEST_F(CollectionFilteringTest, RangeFilterOnTimestamp) {
+    std::vector<field> fields = {field("ts", field_types::INT64, false)};
+
+    Collection* coll1 = collectionManager.create_collection(
+            "coll1", 1, fields, "", 0, "", {}, {"."}
+    ).get();
+
+    nlohmann::json doc1;
+    doc1["id"] = "0";
+    doc1["ts"] = 1646092800000;
+
+    nlohmann::json doc2;
+    doc2["id"] = "1";
+    doc2["ts"] = 1648771199000;
+
+    nlohmann::json doc3;
+    doc3["id"] = "2";
+    doc3["ts"] = 1647111199000;
+
+    ASSERT_TRUE(coll1->add(doc1.dump()).ok());
+    ASSERT_TRUE(coll1->add(doc2.dump()).ok());
+    ASSERT_TRUE(coll1->add(doc3.dump()).ok());
+
+    auto results = coll1->search("*", {},"ts:[1646092800000..1648771199000]", {}, {}, {0}, 10,
+                                 1, FREQUENCY, {false}).get();
+
+    ASSERT_EQ(3, results["hits"].size());
+
+    collectionManager.drop_collection("coll1");
+}
+
 TEST_F(CollectionFilteringTest, QueryBoolFields) {
     Collection *coll_bool;
 
diff --git a/test/collection_schema_change_test.cpp b/test/collection_schema_change_test.cpp
index 3e3fcbf4..bbebe994 100644
--- a/test/collection_schema_change_test.cpp
+++ b/test/collection_schema_change_test.cpp
@@ -710,3 +710,26 @@ TEST_F(CollectionSchemaChangeTest, AddDynamicFieldMatchingMultipleFields) {
     ASSERT_EQ(2, coll1->get_fields().size());
     ASSERT_EQ(0, coll1->get_dynamic_fields().size());
 }
+
+TEST_F(CollectionSchemaChangeTest, DropFieldNotExistingInDocuments) {
+    // optional title field
+    std::vector<field> fields = {field("title", field_types::STRING, false, true, true, "", 1, 1),
+                                 field("points", field_types::INT32, true),};
+
+    Collection* coll1 = collectionManager.create_collection("coll1", 1, fields, "points", 0, "").get();
+
+    nlohmann::json doc;
+    doc["id"] = "0";
+    doc["points"] = 100;
+
+    ASSERT_TRUE(coll1->add(doc.dump()).ok());
+
+    auto schema_changes = R"({
+        "fields": [
+            {"name": "title", "drop": true}
+        ]
+    })"_json;
+
+    auto alter_op = coll1->alter(schema_changes);
+    ASSERT_TRUE(alter_op.ok());
+}
\ No newline at end of file