diff --git a/samples/bluetooth/hci_uart/microbit.conf b/samples/bluetooth/hci_uart/microbit.conf
index ccab2faa658..1f4166e26c7 100644
--- a/samples/bluetooth/hci_uart/microbit.conf
+++ b/samples/bluetooth/hci_uart/microbit.conf
@@ -10,4 +10,6 @@ CONFIG_IDLE_STACK_SIZE=256
 CONFIG_ISR_STACK_SIZE=512
 CONFIG_BT=y
 CONFIG_BT_HCI_RAW=y
-CONFIG_BT_MAX_CONN=16
+CONFIG_BT_MAX_CONN=12
+CONFIG_BT_PHY_UPDATE=n
+CONFIG_BT_DATA_LEN_UPDATE=n
diff --git a/samples/bluetooth/mesh_demo/prj_bbc_microbit.conf b/samples/bluetooth/mesh_demo/prj_bbc_microbit.conf
index 8066cb3ec0b..c95f0816fc2 100644
--- a/samples/bluetooth/mesh_demo/prj_bbc_microbit.conf
+++ b/samples/bluetooth/mesh_demo/prj_bbc_microbit.conf
@@ -13,6 +13,8 @@ CONFIG_BT_RX_STACK_SIZE=1280
 CONFIG_BT_CTLR_DUP_FILTER_LEN=0
 CONFIG_BT_OBSERVER=y
 CONFIG_BT_BROADCASTER=y
+CONFIG_BT_PHY_UPDATE=n
+CONFIG_BT_DATA_LEN_UPDATE=n
 
 CONFIG_BT_MESH=y
 CONFIG_BT_MESH_RELAY=y