diff --git a/src/ModelSnapshot.cpp b/src/ModelSnapshot.cpp
index ec56cd5..d40abae 100644
--- a/src/ModelSnapshot.cpp
+++ b/src/ModelSnapshot.cpp
@@ -126,18 +126,18 @@ void writeGroup(JsonFormatter &json, const group_snapshot_t &group, shade_lookup
 uint8_t nextRoomId(const model_snapshot_t &snap) {
   uint8_t ids[SOMFY_MAX_ROOMS];
   for(uint8_t i = 0; i < snap.roomCount; i++) ids[i] = snap.rooms[i].roomId;
-  return firstFreeId(ids, snap.roomCount, SOMFY_MAX_ROOMS - 2);
+  return firstFreeId(ids, snap.roomCount, SOMFY_MAX_ROOMS);
 }
 uint8_t nextShadeId(const model_snapshot_t &snap) {
   uint8_t ids[SOMFY_MAX_SHADES];
   for(uint8_t i = 0; i < snap.shadeCount; i++) ids[i] = snap.shades[i].shadeId;
-  const uint8_t id = firstFreeId(ids, snap.shadeCount, SOMFY_MAX_SHADES - 2);
+  const uint8_t id = firstFreeId(ids, snap.shadeCount, SOMFY_MAX_SHADES);
   return id == 0 ? 255 : id;
 }
 uint8_t nextGroupId(const model_snapshot_t &snap) {
   uint8_t ids[SOMFY_MAX_GROUPS];
   for(uint8_t i = 0; i < snap.groupCount; i++) ids[i] = snap.groups[i].groupId;
-  const uint8_t id = firstFreeId(ids, snap.groupCount, SOMFY_MAX_GROUPS - 2);
+  const uint8_t id = firstFreeId(ids, snap.groupCount, SOMFY_MAX_GROUPS);
   return id == 0 ? 255 : id;
 }
 uint32_t nextRemoteAddress(const model_snapshot_t &snap, uint8_t id) {
diff --git a/src/ShadeController.cpp b/src/ShadeController.cpp
index 87e0b06..0179832 100644
--- a/src/ShadeController.cpp
+++ b/src/ShadeController.cpp
@@ -151,11 +151,11 @@ void SomfyShadeController::processWaitingFrame() {
     if(this->shades[i].getShadeId() != 255) this->shades[i].processWaitingFrame();
 }
 // A deleted shade, group or room leaves a gap, so a new one takes the lowest
-// free id.  Ids stop two short of the maximum, as they always have.
+// free id, from 1 up to the maximum.
 uint8_t SomfyShadeController::getNextShadeId() {
   uint8_t ids[SOMFY_MAX_SHADES];
   for(uint8_t i = 0; i < SOMFY_MAX_SHADES; i++) ids[i] = this->shades[i].getShadeId();
-  const uint8_t id = firstFreeId(ids, SOMFY_MAX_SHADES, SOMFY_MAX_SHADES - 2);
+  const uint8_t id = firstFreeId(ids, SOMFY_MAX_SHADES, SOMFY_MAX_SHADES);
   return id == 0 ? 255 : id;
 }
 int8_t SomfyShadeController::getMaxShadeOrder() {
@@ -175,13 +175,13 @@ int8_t SomfyShadeController::getMaxGroupOrder() {
 uint8_t SomfyShadeController::getNextGroupId() {
   uint8_t ids[SOMFY_MAX_GROUPS];
   for(uint8_t i = 0; i < SOMFY_MAX_GROUPS; i++) ids[i] = this->groups[i].getGroupId();
-  const uint8_t id = firstFreeId(ids, SOMFY_MAX_GROUPS, SOMFY_MAX_GROUPS - 2);
+  const uint8_t id = firstFreeId(ids, SOMFY_MAX_GROUPS, SOMFY_MAX_GROUPS);
   return id == 0 ? 255 : id;
 }
 uint8_t SomfyShadeController::getNextRoomId() {
   uint8_t ids[SOMFY_MAX_ROOMS];
   for(uint8_t i = 0; i < SOMFY_MAX_ROOMS; i++) ids[i] = this->rooms[i].roomId;
-  return firstFreeId(ids, SOMFY_MAX_ROOMS, SOMFY_MAX_ROOMS - 2);
+  return firstFreeId(ids, SOMFY_MAX_ROOMS, SOMFY_MAX_ROOMS);
 }
 int8_t SomfyShadeController::getMaxRoomOrder() {
   int8_t orders[SOMFY_MAX_ROOMS];
diff --git a/test/test_snapshot/test_snapshot.cpp b/test/test_snapshot/test_snapshot.cpp
index 4984b21..b308782 100644
--- a/test/test_snapshot/test_snapshot.cpp
+++ b/test/test_snapshot/test_snapshot.cpp
@@ -242,9 +242,17 @@ static void test_next_group() {
   TEST_ASSERT_EQUAL_STRING("{\"groupId\":1,\"remoteAddress\":78,\"bitLength\":0,\"proto\":0}",
     document(snapshot_doc_t::nextGroup).c_str());
 }
-static void test_no_room_for_another_shade() {
+static void test_the_last_ids_are_given_out() {
+  // Ids used to stop two short: 30 shades where the limit says 32.
   snap.shadeCount = 0;
   for(uint8_t id = 1; id <= SOMFY_MAX_SHADES - 2; id++) snap.shades[snap.shadeCount++] = shade(id, "S");
+  TEST_ASSERT_EQUAL_UINT8(SOMFY_MAX_SHADES - 1, nextShadeId(snap));
+  snap.shades[snap.shadeCount++] = shade(SOMFY_MAX_SHADES - 1, "S");
+  TEST_ASSERT_EQUAL_UINT8(SOMFY_MAX_SHADES, nextShadeId(snap));
+}
+static void test_no_room_for_another_shade() {
+  snap.shadeCount = 0;
+  for(uint8_t id = 1; id <= SOMFY_MAX_SHADES; id++) snap.shades[snap.shadeCount++] = shade(id, "S");
   TEST_ASSERT_EQUAL_UINT8(255, nextShadeId(snap));
 }
 static void test_group_options_lists_the_shades_not_in_it() {
@@ -334,6 +342,7 @@ int main(int argc, char **argv) {
   RUN_TEST(test_next_shade);
   RUN_TEST(test_next_address_skips_one_already_used);
   RUN_TEST(test_next_group);
+  RUN_TEST(test_the_last_ids_are_given_out);
   RUN_TEST(test_no_room_for_another_shade);
   RUN_TEST(test_group_options_lists_the_shades_not_in_it);
   RUN_TEST(test_group_options_of_a_group_gone_by_the_snapshot);