diff --git a/xen/arch/x86/arch.mk b/xen/arch/x86/arch.mk
index 9dde8a5756f2..cb47d729911e 100644
--- a/xen/arch/x86/arch.mk
+++ b/xen/arch/x86/arch.mk
@@ -109,7 +109,7 @@ endif
 ifeq ($(XEN_BUILD_PE),y)
 
 # Check if the linker produces fixups in PE by default
-efi-nr-fixups := $(shell $(OBJDUMP) -p $(efi-check).efi | grep '^[[:blank:]]*reloc[[:blank:]]*[0-9][[:blank:]].*DIR64$$' | wc -l)
+efi-nr-fixups := $(shell LC_ALL=C $(OBJDUMP) -p $(efi-check).efi | grep '^[[:blank:]]*reloc[[:blank:]]*[0-9][[:blank:]].*DIR64$$' | wc -l)
 
 ifeq ($(efi-nr-fixups),2)
 MKRELOC := :