diff --git a/OvmfPkg/OvmfPkgIa32X64.dsc b/OvmfPkg/OvmfPkgIa32X64.dsc
index f6588c5ede..1a5a9012ee 100644
--- a/OvmfPkg/OvmfPkgIa32X64.dsc
+++ b/OvmfPkg/OvmfPkgIa32X64.dsc
@@ -636,11 +636,7 @@
   gUefiOvmfPkgTokenSpaceGuid.PcdPciMmio32Base|0x0
   gUefiOvmfPkgTokenSpaceGuid.PcdPciMmio32Size|0x0
   gUefiOvmfPkgTokenSpaceGuid.PcdPciMmio64Base|0x0
-!ifdef $(CSM_ENABLE)
-  gUefiOvmfPkgTokenSpaceGuid.PcdPciMmio64Size|0x0
-!else
   gUefiOvmfPkgTokenSpaceGuid.PcdPciMmio64Size|0x800000000
-!endif
 
   gEfiMdePkgTokenSpaceGuid.PcdPlatformBootTimeOut|0
 
diff --git a/OvmfPkg/OvmfPkgX64.dsc b/OvmfPkg/OvmfPkgX64.dsc
index 879799a0f1..44d163aac1 100644
--- a/OvmfPkg/OvmfPkgX64.dsc
+++ b/OvmfPkg/OvmfPkgX64.dsc
@@ -654,11 +654,7 @@
   gUefiOvmfPkgTokenSpaceGuid.PcdPciMmio32Base|0x0
   gUefiOvmfPkgTokenSpaceGuid.PcdPciMmio32Size|0x0
   gUefiOvmfPkgTokenSpaceGuid.PcdPciMmio64Base|0x0
-!ifdef $(CSM_ENABLE)
-  gUefiOvmfPkgTokenSpaceGuid.PcdPciMmio64Size|0x0
-!else
   gUefiOvmfPkgTokenSpaceGuid.PcdPciMmio64Size|0x800000000
-!endif
 
   gEfiMdePkgTokenSpaceGuid.PcdPlatformBootTimeOut|0