diff --git a/elfcpp/elfcpp.h b/elfcpp/elfcpp.h
index 0e6833f60b..30edaa18aa 100644
--- a/elfcpp/elfcpp.h
+++ b/elfcpp/elfcpp.h
@@ -142,6 +142,7 @@ enum ELFOSABI
   ELFOSABI_OPENVMS = 13,
   ELFOSABI_NSK = 14,
   ELFOSABI_AROS = 15,
+  ELFOSABI_HERMIT = 66,
   // A GNU extension for the ARM.
   ELFOSABI_ARM = 97,
   // A GNU extension for the MSP.
diff --git a/include/elf/common.h b/include/elf/common.h
index ea2345b0c1..fc84883a73 100644
--- a/include/elf/common.h
+++ b/include/elf/common.h
@@ -73,10 +73,10 @@
 #define ELFOSABI_NSK	     14	/* Hewlett-Packard Non-Stop Kernel */
 #define ELFOSABI_AROS	     15	/* AROS */
 #define ELFOSABI_FENIXOS     16 /* FenixOS */
-#define ELFOSABI_HERMIT    0x42 /* HermitCore */
 #define ELFOSABI_CLOUDABI    17 /* Nuxi CloudABI */
 #define ELFOSABI_C6000_ELFABI 64 /* Bare-metal TMS320C6000 */
 #define ELFOSABI_C6000_LINUX 65 /* Linux TMS320C6000 */
+#define ELFOSABI_HERMIT      66 /* HermitCore */
 #define ELFOSABI_ARM	     97	/* ARM */
 #define ELFOSABI_STANDALONE 255	/* Standalone (embedded) application */