diff --git a/OvmfPkg/OvmfPkgIa32.dsc b/OvmfPkg/OvmfPkgIa32.dsc
index 578fc6c98e..e74a9d5a51 100644
--- a/OvmfPkg/OvmfPkgIa32.dsc
+++ b/OvmfPkg/OvmfPkgIa32.dsc
@@ -492,8 +492,8 @@
   # the PCIEXBAR register.
   #
   # On Q35 machine types that QEMU intends to support in the long term, QEMU
-  # never lets the RAM below 4 GB exceed 2 GB.
-  gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0x80000000
+  # never lets the RAM below 4 GB exceed 2816 MB.
+  gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0xB0000000
 
 !ifdef $(SOURCE_DEBUG_ENABLE)
   gEfiSourceLevelDebugPkgTokenSpaceGuid.PcdDebugLoadImageMethod|0x2
diff --git a/OvmfPkg/OvmfPkgIa32X64.dsc b/OvmfPkg/OvmfPkgIa32X64.dsc
index eade8f62d3..67ac015991 100644
--- a/OvmfPkg/OvmfPkgIa32X64.dsc
+++ b/OvmfPkg/OvmfPkgIa32X64.dsc
@@ -497,8 +497,8 @@
   # the PCIEXBAR register.
   #
   # On Q35 machine types that QEMU intends to support in the long term, QEMU
-  # never lets the RAM below 4 GB exceed 2 GB.
-  gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0x80000000
+  # never lets the RAM below 4 GB exceed 2816 MB.
+  gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0xB0000000
 
 !ifdef $(SOURCE_DEBUG_ENABLE)
   gEfiSourceLevelDebugPkgTokenSpaceGuid.PcdDebugLoadImageMethod|0x2
diff --git a/OvmfPkg/OvmfPkgX64.dsc b/OvmfPkg/OvmfPkgX64.dsc
index 733a4c9d8a..68073ef55b 100644
--- a/OvmfPkg/OvmfPkgX64.dsc
+++ b/OvmfPkg/OvmfPkgX64.dsc
@@ -497,8 +497,8 @@
   # the PCIEXBAR register.
   #
   # On Q35 machine types that QEMU intends to support in the long term, QEMU
-  # never lets the RAM below 4 GB exceed 2 GB.
-  gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0x80000000
+  # never lets the RAM below 4 GB exceed 2816 MB.
+  gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0xB0000000
 
 !ifdef $(SOURCE_DEBUG_ENABLE)
   gEfiSourceLevelDebugPkgTokenSpaceGuid.PcdDebugLoadImageMethod|0x2