diff --git a/OvmfPkg/Library/PciHostBridgeLib/PciHostBridgeLib.c b/OvmfPkg/Library/PciHostBridgeLib/PciHostBridgeLib.c
index b23939d166..cc782c1cc3 100644
--- a/OvmfPkg/Library/PciHostBridgeLib/PciHostBridgeLib.c
+++ b/OvmfPkg/Library/PciHostBridgeLib/PciHostBridgeLib.c
@@ -101,6 +101,8 @@ InitRootBridge (
   RootBus->Mem.Limit = PcdGet64 (PcdPciMmio32Base) +
                        (PcdGet64 (PcdPciMmio32Size) - 1);
 
+  RootBus->NoExtendedConfigSpace = TRUE;
+
   return EFI_OUT_OF_RESOURCES;
 }