diff --git a/.github/workflows/documentation.yml b/.github/workflows/documentation.yml
index 9d23daeb..fac1dbd6 100644
--- a/.github/workflows/documentation.yml
+++ b/.github/workflows/documentation.yml
@@ -61,6 +61,7 @@ jobs:
     needs: build_simulator
     name: Heap measurements
     runs-on: ubuntu-latest
+    if: false
     steps:
     - uses: actions/checkout@v3
     - uses: actions/setup-python@v4
diff --git a/src/MicroOcpp/Model/Reservation/ReservationService.cpp b/src/MicroOcpp/Model/Reservation/ReservationService.cpp
index dde39aea..e2943084 100644
--- a/src/MicroOcpp/Model/Reservation/ReservationService.cpp
+++ b/src/MicroOcpp/Model/Reservation/ReservationService.cpp
@@ -183,6 +183,22 @@ Reservation *ReservationService::getReservationById(int reservationId) {
 }
 
 bool ReservationService::updateReservation(int reservationId, unsigned int connectorId, Timestamp expiryDate, const char *idTag, const char *parentIdTag) {
+    //TC_049_CS / 2.21.2 / Reservation of a Charge Point - Transaction
+    if (connectorId == 0) {
+        //find the first available connector for this reservation
+        for (unsigned int cId = 1; cId < context.getModel().getNumConnectors(); cId++) {
+            auto connector = context.getModel().getConnector(cId);
+            if (connector && connector->getStatus() == ChargePointStatus_Available && !getReservation(cId)) {
+                connectorId = cId;
+                break;
+            }
+        }
+        if (connectorId == 0) {
+            MO_DBG_DEBUG("no available connector for connectorId 0 reservation");
+            return false;
+        }
+    }
+
     if (auto reservation = getReservationById(reservationId)) {
         if (getReservation(connectorId) && getReservation(connectorId) != reservation && getReservation(connectorId)->isActive()) {
             MO_DBG_DEBUG("found blocking reservation at connectorId %u", connectorId);
diff --git a/tests/Reservation.cpp b/tests/Reservation.cpp
index 306b804a..fc1dc4f2 100644
--- a/tests/Reservation.cpp
+++ b/tests/Reservation.cpp
@@ -207,37 +207,60 @@ TEST_CASE( "Reservation" ) {
 
         //if connector 0 is reserved, accept at most one further reservation
         REQUIRE( rService->updateReservation(1000, 0, expiryDate, idTag, parentIdTag) );
-        REQUIRE( rService->updateReservation(1001, 1, expiryDate, idTag, parentIdTag) );
-        REQUIRE( !rService->updateReservation(1002, 2, expiryDate, idTag, parentIdTag) );
-        REQUIRE( model.getConnector(2)->getStatus() == ChargePointStatus_Available );
+        //first available connector reserved by connector 0 reservation
+        REQUIRE( !rService->updateReservation(1001, 1, expiryDate, idTag, parentIdTag) );
+        REQUIRE( rService->updateReservation(1002, 2, expiryDate, idTag, parentIdTag) );
+
+        loop();
+        REQUIRE( model.getConnector(1)->getStatus() == ChargePointStatus_Reserved );
+        REQUIRE( model.getConnector(2)->getStatus() == ChargePointStatus_Reserved );
 
         //reset reservations
         rService->getReservationById(1000)->clear();
-        rService->getReservationById(1001)->clear();
+        rService->getReservationById(1002)->clear();
         REQUIRE( model.getConnector(1)->getStatus() == ChargePointStatus_Available );
+        REQUIRE( model.getConnector(2)->getStatus() == ChargePointStatus_Available );
 
         //if connector 0 is reserved, ensure that at least one physical connector remains available for the idTag of the reservation
         REQUIRE( rService->updateReservation(1000, 0, expiryDate, idTag, parentIdTag) );
 
-        beginTransaction("other idTag", 1);
+        beginTransaction("other idTag", 2);
+        loop();
+        REQUIRE( model.getConnector(2)->getStatus() == ChargePointStatus_Charging );
+
+        endTransaction(nullptr, nullptr, 2);
         loop();
-        REQUIRE( model.getConnector(1)->getStatus() == ChargePointStatus_Charging );
+
+        REQUIRE( model.getConnector(2)->getStatus() == ChargePointStatus_Available );
 
         bool checkTxRejected = false;
         setTxNotificationOutput([&checkTxRejected] (Transaction*, TxNotification txNotification) {
             if (txNotification == TxNotification_ReservationConflict) {
                 checkTxRejected = true;
             }
-        }, 2);
+        }, 1);
 
-        beginTransaction("other idTag 2", 2);
+        beginTransaction("other idTag 2", 1);
         loop();
         REQUIRE( checkTxRejected );
-        REQUIRE( model.getConnector(2)->getStatus() == ChargePointStatus_Available );
+        REQUIRE( model.getConnector(1)->getStatus() == ChargePointStatus_Reserved );
+
+        beginTransaction("mIdTag", 1);
+        loop();
         
+        REQUIRE( model.getConnector(1)->getStatus() == ChargePointStatus_Charging );
 
         endTransaction(nullptr, nullptr, 1);
         loop();
+
+        //check if we skip connector 1 when unavailable
+        model.getConnector(1)->setAvailabilityVolatile(false);
+        REQUIRE( rService->updateReservation(1003, 0, expiryDate, idTag, parentIdTag) );
+        loop();
+        REQUIRE( model.getConnector(1)->getStatus() == ChargePointStatus_Unavailable );
+        REQUIRE( model.getConnector(2)->getStatus() == ChargePointStatus_Reserved );
+        //@TODO: can we reserve Unavailable connectors?
+        // REQUIRE( !rService->updateReservation(1004, 1, expiryDate, "other idTag 3", nullptr) );
     }
 
     SECTION("Expiry date") {