diff --git a/litex/tools/litex_sim.py b/litex/tools/litex_sim.py
index 961c3635e..633562389 100755
--- a/litex/tools/litex_sim.py
+++ b/litex/tools/litex_sim.py
@@ -98,9 +98,7 @@ class Platform(SimPlatform):
 # Simulation SoC -----------------------------------------------------------------------------------
 
 class SimSoC(SoCCore):
-    mem_map = {
-        "spiflash" : 0x80000000,
-    }
+    mem_map = {**SoCCore.mem_map, **{"spiflash": 0x80000000}}
     def __init__(self,
         with_sdram            = False,
         with_ethernet         = False,