diff --git a/samples/bluetooth/mesh_demo/prj.conf b/samples/bluetooth/mesh_demo/prj.conf
index 1eeb3d309c3..144e9440a9c 100644
--- a/samples/bluetooth/mesh_demo/prj.conf
+++ b/samples/bluetooth/mesh_demo/prj.conf
@@ -15,6 +15,7 @@ CONFIG_BT_MESH_ADV_BUF_COUNT=10
 CONFIG_BT_MESH_LABEL_COUNT=0
 CONFIG_BT_MESH_PB_ADV=n
 CONFIG_BT_MESH_CFG_CLI=y
+CONFIG_BT_MESH_LOOPBACK_BUFS=8
 
 CONFIG_BT_SETTINGS=y
 CONFIG_FLASH=y
diff --git a/samples/bluetooth/mesh_demo/prj_bbc_microbit.conf b/samples/bluetooth/mesh_demo/prj_bbc_microbit.conf
index 4317bff7a84..4ce3336ab75 100644
--- a/samples/bluetooth/mesh_demo/prj_bbc_microbit.conf
+++ b/samples/bluetooth/mesh_demo/prj_bbc_microbit.conf
@@ -1,6 +1,6 @@
 CONFIG_ISR_STACK_SIZE=768
 CONFIG_MAIN_STACK_SIZE=512
-CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=2048
+CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=1200
 CONFIG_GPIO=y
 CONFIG_DISPLAY=y
 CONFIG_MICROBIT_DISPLAY=y
@@ -22,7 +22,7 @@ CONFIG_BT_MESH_SUBNET_COUNT=1
 CONFIG_BT_MESH_APP_KEY_COUNT=2
 CONFIG_BT_MESH_MODEL_GROUP_COUNT=2
 CONFIG_BT_MESH_ADV_BUF_COUNT=3
-CONFIG_BT_MESH_LOOPBACK_BUFS=1
+CONFIG_BT_MESH_LOOPBACK_BUFS=8
 CONFIG_BT_MESH_PB_ADV=n
 CONFIG_BT_MESH_CFG_CLI=y
 CONFIG_BT_MESH_BEACON_ENABLED=n
diff --git a/samples/bluetooth/mesh_demo/prj_nrf51_blenano.conf b/samples/bluetooth/mesh_demo/prj_nrf51_blenano.conf
index cff3548d6d9..09b53e46aec 100644
--- a/samples/bluetooth/mesh_demo/prj_nrf51_blenano.conf
+++ b/samples/bluetooth/mesh_demo/prj_nrf51_blenano.conf
@@ -1,9 +1,11 @@
 CONFIG_MAIN_STACK_SIZE=512
+CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=1200
 
 CONFIG_BT=y
 CONFIG_BT_TINYCRYPT_ECC=y
 CONFIG_BT_RX_STACK_SIZE=1100
 CONFIG_BT_CTLR_DUP_FILTER_LEN=0
+CONFIG_BT_MESH_LOOPBACK_BUFS=8
 CONFIG_BT_OBSERVER=y
 CONFIG_BT_BROADCASTER=y