diff --git a/libcanard/canard.c b/libcanard/canard.c
index 61992742..5a555bc5 100644
--- a/libcanard/canard.c
+++ b/libcanard/canard.c
@@ -1382,9 +1382,11 @@ int8_t canardRxSubscribe(struct CanardInstance* const       ins,
                          const CanardMicrosecond            transfer_id_timeout_usec,
                          struct CanardRxSubscription* const out_subscription)
 {
-    int8_t       out = -CANARD_ERROR_INVALID_ARGUMENT;
-    const size_t tk  = (size_t) transfer_kind;
-    if ((ins != NULL) && (out_subscription != NULL) && (tk < CANARD_NUM_TRANSFER_KINDS))
+    int8_t       out        = -CANARD_ERROR_INVALID_ARGUMENT;
+    const size_t tk         = (size_t) transfer_kind;
+    const bool   port_id_ok = ((transfer_kind == CanardTransferKindMessage) && (port_id <= CANARD_SUBJECT_ID_MAX)) ||
+                            (port_id <= CANARD_SERVICE_ID_MAX);
+    if ((ins != NULL) && (out_subscription != NULL) && (tk < CANARD_NUM_TRANSFER_KINDS) && port_id_ok)
     {
         // Reset to the initial state. This is absolutely critical because the new payload size limit may be larger
         // than the old value; if there are any payload buffers allocated, we may overrun them because they are shorter
diff --git a/tests/test_public_rx.cpp b/tests/test_public_rx.cpp
index 371306fa..40a9d688 100644
--- a/tests/test_public_rx.cpp
+++ b/tests/test_public_rx.cpp
@@ -369,6 +369,10 @@ TEST_CASE("RxSubscriptionErrors")
     REQUIRE(-CANARD_ERROR_INVALID_ARGUMENT == canardRxSubscribe(&ins.getInstance(), kind.value, 0, 0, 0, &sub));
     REQUIRE(-CANARD_ERROR_INVALID_ARGUMENT ==
             canardRxSubscribe(&ins.getInstance(), CanardTransferKindMessage, 0, 0, 0, nullptr));
+    REQUIRE(-CANARD_ERROR_INVALID_ARGUMENT ==
+            canardRxSubscribe(&ins.getInstance(), CanardTransferKindMessage, 8192, 0, 0, &sub));
+    REQUIRE(-CANARD_ERROR_INVALID_ARGUMENT ==
+            canardRxSubscribe(&ins.getInstance(), CanardTransferKindResponse, 512, 0, 0, &sub));
 
     REQUIRE(-CANARD_ERROR_INVALID_ARGUMENT == canardRxUnsubscribe(nullptr, CanardTransferKindMessage, 0));
     REQUIRE(-CANARD_ERROR_INVALID_ARGUMENT == canardRxUnsubscribe(&ins.getInstance(), kind.value, 0));