diff --git a/arch/z80/include/z80/types.h b/arch/z80/include/z80/types.h
index fb774dd75e3..021152b3595 100644
--- a/arch/z80/include/z80/types.h
+++ b/arch/z80/include/z80/types.h
@@ -84,6 +84,9 @@ typedef signed long long   _int64_t;
 typedef unsigned long long _uint64_t;
 #define __INT64_DEFINED
 
+typedef _int64_t           _intmax_t;
+typedef _uint64_t          _uintmax_t;
+
 /* A size is 2 bytes */
 
 #if defined(__SIZE_TYPE__)