diff --git a/libc/arch-x86_64/include/machine/elf_machdep.h b/libc/arch-x86_64/include/machine/elf_machdep.h
index 20f8c6d..bf1f273 100644
--- a/libc/arch-x86_64/include/machine/elf_machdep.h
+++ b/libc/arch-x86_64/include/machine/elf_machdep.h
@@ -46,6 +46,8 @@
 #define R_X86_64_GOTTPOFF	22
 #define R_X86_64_TPOFF32	23
 
+#define R_X86_64_IRELATIVE	37
+
 #define	R_TYPE(name)	__CONCAT(R_X86_64_,name)
 
 #else	/*	!__i386__	*/