diff --git a/OvmfPkg/OvmfPkgIa32.dsc b/OvmfPkg/OvmfPkgIa32.dsc
index 4301e78219..05bb6ae136 100644
--- a/OvmfPkg/OvmfPkgIa32.dsc
+++ b/OvmfPkg/OvmfPkgIa32.dsc
@@ -67,7 +67,7 @@
   GCC:RELEASE_*_*_CC_FLAGS             = -DMDEPKG_NDEBUG
   INTEL:RELEASE_*_*_CC_FLAGS           = /D MDEPKG_NDEBUG
   MSFT:RELEASE_*_*_CC_FLAGS            = /D MDEPKG_NDEBUG
-!if $(TOOL_CHAIN_TAG) != "XCODE5"
+!if $(TOOL_CHAIN_TAG) != "XCODE5" && $(TOOL_CHAIN_TAG) != "CLANG9"
   GCC:*_*_*_CC_FLAGS                   = -mno-mmx -mno-sse
 !endif
 
@@ -81,12 +81,14 @@
 [BuildOptions.common.EDKII.DXE_RUNTIME_DRIVER]
   GCC:*_*_*_DLINK_FLAGS = -z common-page-size=0x1000
   XCODE:*_*_*_DLINK_FLAGS =
+  CLANGPE: *_*_*_DLINK_FLAGS = /ALIGN:4096
 
 # Force PE/COFF sections to be aligned at 4KB boundaries to support page level
 # protection of DXE_SMM_DRIVER/SMM_CORE modules
 [BuildOptions.common.EDKII.DXE_SMM_DRIVER, BuildOptions.common.EDKII.SMM_CORE]
   GCC:*_*_*_DLINK_FLAGS = -z common-page-size=0x1000
   XCODE:*_*_*_DLINK_FLAGS =
+  CLANGPE: *_*_*_DLINK_FLAGS = /ALIGN:4096
 
 ################################################################################
 #
diff --git a/OvmfPkg/OvmfPkgIa32X64.dsc b/OvmfPkg/OvmfPkgIa32X64.dsc
index 803fd74ae8..4a75a0332e 100644
--- a/OvmfPkg/OvmfPkgIa32X64.dsc
+++ b/OvmfPkg/OvmfPkgIa32X64.dsc
@@ -67,7 +67,7 @@
   GCC:RELEASE_*_*_CC_FLAGS             = -DMDEPKG_NDEBUG
   INTEL:RELEASE_*_*_CC_FLAGS           = /D MDEPKG_NDEBUG
   MSFT:RELEASE_*_*_CC_FLAGS            = /D MDEPKG_NDEBUG
-!if $(TOOL_CHAIN_TAG) != "XCODE5"
+!if $(TOOL_CHAIN_TAG) != "XCODE5" && $(TOOL_CHAIN_TAG) != "CLANG9"
   GCC:*_*_*_CC_FLAGS                   = -mno-mmx -mno-sse
 !endif
 !if $(SOURCE_DEBUG_ENABLE) == TRUE
@@ -86,12 +86,14 @@
 [BuildOptions.common.EDKII.DXE_RUNTIME_DRIVER]
   GCC:*_*_*_DLINK_FLAGS = -z common-page-size=0x1000
   XCODE:*_*_*_DLINK_FLAGS =
+  CLANGPE: *_*_*_DLINK_FLAGS = /ALIGN:4096
 
 # Force PE/COFF sections to be aligned at 4KB boundaries to support page level
 # protection of DXE_SMM_DRIVER/SMM_CORE modules
 [BuildOptions.common.EDKII.DXE_SMM_DRIVER, BuildOptions.common.EDKII.SMM_CORE]
   GCC:*_*_*_DLINK_FLAGS = -z common-page-size=0x1000
   XCODE:*_*_*_DLINK_FLAGS =
+  CLANGPE: *_*_*_DLINK_FLAGS = /ALIGN:4096
 
 ################################################################################
 #
diff --git a/OvmfPkg/OvmfPkgX64.dsc b/OvmfPkg/OvmfPkgX64.dsc
index 5dbd1b793a..ed54181180 100644
--- a/OvmfPkg/OvmfPkgX64.dsc
+++ b/OvmfPkg/OvmfPkgX64.dsc
@@ -67,7 +67,7 @@
   GCC:RELEASE_*_*_CC_FLAGS             = -DMDEPKG_NDEBUG
   INTEL:RELEASE_*_*_CC_FLAGS           = /D MDEPKG_NDEBUG
   MSFT:RELEASE_*_*_CC_FLAGS            = /D MDEPKG_NDEBUG
-!if $(TOOL_CHAIN_TAG) != "XCODE5"
+!if $(TOOL_CHAIN_TAG) != "XCODE5" && $(TOOL_CHAIN_TAG) != "CLANG9"
   GCC:*_*_*_CC_FLAGS                   = -mno-mmx -mno-sse
 !endif
 !if $(SOURCE_DEBUG_ENABLE) == TRUE
@@ -86,12 +86,14 @@
 [BuildOptions.common.EDKII.DXE_RUNTIME_DRIVER]
   GCC:*_*_*_DLINK_FLAGS = -z common-page-size=0x1000
   XCODE:*_*_*_DLINK_FLAGS =
+  CLANGPE: *_*_*_DLINK_FLAGS = /ALIGN:4096
 
 # Force PE/COFF sections to be aligned at 4KB boundaries to support page level
 # protection of DXE_SMM_DRIVER/SMM_CORE modules
 [BuildOptions.common.EDKII.DXE_SMM_DRIVER, BuildOptions.common.EDKII.SMM_CORE]
   GCC:*_*_*_DLINK_FLAGS = -z common-page-size=0x1000
   XCODE:*_*_*_DLINK_FLAGS =
+  CLANGPE: *_*_*_DLINK_FLAGS = /ALIGN:4096
 
 ################################################################################
 #