diff --git a/Libraries/LibWeb/IndexedDB/IDBTransaction.h b/Libraries/LibWeb/IndexedDB/IDBTransaction.h
index 5ca6ee15325..194d40c7023 100644
--- a/Libraries/LibWeb/IndexedDB/IDBTransaction.h
+++ b/Libraries/LibWeb/IndexedDB/IDBTransaction.h
@@ -56,6 +56,7 @@ public:
     [[nodiscard]] bool is_upgrade_transaction() const { return m_mode == Bindings::IDBTransactionMode::Versionchange; }
     [[nodiscard]] bool is_readonly() const { return m_mode == Bindings::IDBTransactionMode::Readonly; }
     [[nodiscard]] bool is_readwrite() const { return m_mode == Bindings::IDBTransactionMode::Readwrite; }
+    [[nodiscard]] bool is_finished() const { return m_state == TransactionState::Finished; }
 
     WebIDL::ExceptionOr<void> abort();
 
diff --git a/Libraries/LibWeb/IndexedDB/Internal/Algorithms.cpp b/Libraries/LibWeb/IndexedDB/Internal/Algorithms.cpp
index e51d4822afb..abfe6d31b8d 100644
--- a/Libraries/LibWeb/IndexedDB/Internal/Algorithms.cpp
+++ b/Libraries/LibWeb/IndexedDB/Internal/Algorithms.cpp
@@ -315,16 +315,41 @@ ErrorOr<GC::Ref<Key>> convert_a_value_to_a_key(JS::Realm& realm, JS::Value input
 // https://w3c.github.io/IndexedDB/#close-a-database-connection
 void close_a_database_connection(GC::Ref<IDBDatabase> connection, bool forced)
 {
+    auto& realm = connection->realm();
+
     // 1. Set connection’s close pending flag to true.
     connection->set_close_pending(true);
 
-    // FIXME: 2. If the forced flag is true, then for each transaction created using connection run abort a transaction with transaction and newly created "AbortError" DOMException.
-    // FIXME: 3. Wait for all transactions created using connection to complete. Once they are complete, connection is closed.
+    // 2. If the forced flag is true, then for each transaction created using connection run abort a transaction with transaction and newly created "AbortError" DOMException.
+    if (forced) {
+        for (auto const& transaction : connection->transactions()) {
+            abort_a_transaction(*transaction, WebIDL::AbortError::create(realm, "Connection was closed"_string));
+        }
+    }
+
+    // 3. Wait for all transactions created using connection to complete. Once they are complete, connection is closed.
+    HTML::main_thread_event_loop().spin_until(GC::create_function(realm.vm().heap(), [connection]() {
+        if constexpr (IDB_DEBUG) {
+            dbgln("close_a_database_connection: waiting for step 3");
+            dbgln("transactions created using connection:");
+            for (auto const& transaction : connection->transactions()) {
+                dbgln("  - {} - {}", transaction->uuid(), (u8)transaction->state());
+            }
+        }
+
+        for (auto const& transaction : connection->transactions()) {
+            if (!transaction->is_finished())
+                return false;
+        }
+
+        return true;
+    }));
+
     connection->set_state(IDBDatabase::ConnectionState::Closed);
 
     // 4. If the forced flag is true, then fire an event named close at connection.
     if (forced)
-        connection->dispatch_event(DOM::Event::create(connection->realm(), HTML::EventNames::close));
+        connection->dispatch_event(DOM::Event::create(realm, HTML::EventNames::close));
 }
 
 // https://w3c.github.io/IndexedDB/#upgrade-a-database