diff --git a/device/mellanox/x86_64-nvidia_sn5640_simx-r0/ACS-SN5640/sai.profile b/device/mellanox/x86_64-nvidia_sn5640_simx-r0/ACS-SN5640/sai.profile
index a1d251ac1ad..fc98a5ebf90 100644
--- a/device/mellanox/x86_64-nvidia_sn5640_simx-r0/ACS-SN5640/sai.profile
+++ b/device/mellanox/x86_64-nvidia_sn5640_simx-r0/ACS-SN5640/sai.profile
@@ -1 +1,4 @@
 SAI_INIT_CONFIG_FILE=/usr/share/sonic/hwsku/sai_5640.xml
+SAI_KEY_SPC5_LOSSY_SCHEDULING=1
+SAI_DEFAULT_SWITCHING_MODE_STORE_FORWARD=1
+