diff --git a/arch/um/include/common-offsets.h b/arch/um/include/common-offsets.h
index 0aa620970ad..782ac3a3baf 100644
--- a/arch/um/include/common-offsets.h
+++ b/arch/um/include/common-offsets.h
@@ -12,4 +12,6 @@ DEFINE_STR(UM_KERN_WARNING, KERN_WARNING);
 DEFINE_STR(UM_KERN_NOTICE, KERN_NOTICE);
 DEFINE_STR(UM_KERN_INFO, KERN_INFO);
 DEFINE_STR(UM_KERN_DEBUG, KERN_DEBUG);
-DEFINE(HOST_ELF_CLASS, ELF_CLASS);
+DEFINE(UM_ELF_CLASS, ELF_CLASS);
+DEFINE(UM_ELFCLASS32, ELFCLASS32);
+DEFINE(UM_ELFCLASS64, ELFCLASS64);
diff --git a/arch/um/os-Linux/elf_aux.c b/arch/um/os-Linux/elf_aux.c
index e770cb02957..ab33cb3c74e 100644
--- a/arch/um/os-Linux/elf_aux.c
+++ b/arch/um/os-Linux/elf_aux.c
@@ -14,7 +14,8 @@
 #include "mem_user.h"
 #include <kernel-offsets.h>
 
-#if HOST_ELF_CLASS == ELFCLASS32
+/* Use the one from the kernel - the host may miss it, if having old headers. */
+#if UM_ELF_CLASS == UM_ELFCLASS32
 typedef Elf32_auxv_t elf_auxv_t;
 #else
 typedef Elf64_auxv_t elf_auxv_t;