diff --git a/xen/arch/x86/Kconfig b/xen/arch/x86/Kconfig
index fe89fa7274..1465874097 100644
--- a/xen/arch/x86/Kconfig
+++ b/xen/arch/x86/Kconfig
@@ -33,7 +33,8 @@ config ARCH_DEFCONFIG
 	default "arch/x86/configs/x86_64_defconfig"
 
 config CC_HAS_INDIRECT_THUNK
-	def_bool $(cc-option,-mindirect-branch-register)
+	def_bool $(cc-option,-mindirect-branch-register) || \
+	         $(cc-option,-mretpoline-external-thunk)
 
 config INDIRECT_THUNK
 	def_bool y
diff --git a/xen/arch/x86/arch.mk b/xen/arch/x86/arch.mk
index 15d0cbe487..edfc043dbb 100644
--- a/xen/arch/x86/arch.mk
+++ b/xen/arch/x86/arch.mk
@@ -47,6 +47,9 @@ ifeq ($(CONFIG_INDIRECT_THUNK),y)
 CFLAGS-$(CONFIG_CC_IS_GCC) += -mindirect-branch=thunk-extern
 CFLAGS-$(CONFIG_CC_IS_GCC) += -mindirect-branch-register
 CFLAGS-$(CONFIG_CC_IS_GCC) += -fno-jump-tables
+
+# Enable clang retpoline support if available.
+CFLAGS-$(CONFIG_CC_IS_CLANG) += -mretpoline-external-thunk
 endif
 
 # If supported by the compiler, reduce stack alignment to 8 bytes. But allow