diff --git a/platform/mellanox/fw.mk b/platform/mellanox/fw.mk
index 3ce64c1ef30a..d7ac41d06761 100644
--- a/platform/mellanox/fw.mk
+++ b/platform/mellanox/fw.mk
@@ -21,6 +21,8 @@ MLNX_FW_BASE_PATH = $(MLNX_SDK_BASE_PATH)
 # Place an URL here to FW if you want to download FW instead
 MLNX_FW_BASE_URL =
 
+SIMX_VERSION = 5.1-1065
+
 ifneq ($(MLNX_FW_BASE_URL), )
 FW_FROM_URL = y
 else