diff --git a/config.h.in b/config.h.in
index 5d8a520..301aa5e 100644
--- a/config.h.in
+++ b/config.h.in
@@ -165,9 +165,15 @@
 /* Define to 1 if you have the <machine/reloc.h> header file. */
 #undef HAVE_MACHINE_RELOC_H
 
+/* Define to 1 if you have the <mach-o/arm64/reloc.h> header file. */
+#undef HAVE_MACH_O_ARM64_RELOC_H
+
 /* Define to 1 if you have the <mach-o/reloc.h> header file. */
 #undef HAVE_MACH_O_RELOC_H
 
+/* Define to 1 if you have the <mach-o/x86_64/reloc.h> header file. */
+#undef HAVE_MACH_O_X86_64_RELOC_H
+
 /* Define to 1 if you have the <malloc.h> header file. */
 #undef HAVE_MALLOC_H
 
diff --git a/configure b/configure
index dee7330..d934d82 100755
--- a/configure
+++ b/configure
@@ -18822,6 +18822,19 @@ fi
 
 done
 
+for ac_header in mach-o/x86_64/reloc.h mach-o/arm64/reloc.h
+do :
+  as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
+ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"
+if eval test \"x\$"$as_ac_Header"\" = x"yes"; then :
+  cat >>confdefs.h <<_ACEOF
+#define `$as_echo "HAVE_$ac_header" | $as_tr_cpp` 1
+_ACEOF
+
+fi
+
+done
+
 for ac_header in windows.h tchar.h semaphore.h
 do :
   as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
diff --git a/configure.ac b/configure.ac
index 9f93a95..a282259 100644
--- a/configure.ac
+++ b/configure.ac
@@ -111,6 +111,7 @@ AC_CHECK_HEADERS([stdarg.h sys/errno.h sys/filio.h sys/mman.h sys/resource.h])
 AC_CHECK_HEADERS([sys/sockio.h sys/stat.h termios.h sys/times.h])
 AC_CHECK_HEADERS([sys/types.h sys/uio.h sys/un.h sys/utsname.h sys/select.h sys/sysctl.h])
 AC_CHECK_HEADERS([sys/elf_SPARC.h sys/elf_386.h sys/elf_amd64.h asm/elf.h machine/reloc.h i386/elf_machdep.h])
+AC_CHECK_HEADERS([mach-o/x86_64/reloc.h mach-o/arm64/reloc.h])
 AC_CHECK_HEADERS([windows.h tchar.h semaphore.h])
 AC_CHECK_HEADERS([stdint.h inttypes.h])
 
diff --git a/libpolyml/machoexport.cpp b/libpolyml/machoexport.cpp
index 1fcb020..4b18b4e 100644
--- a/libpolyml/machoexport.cpp
+++ b/libpolyml/machoexport.cpp
@@ -55,9 +55,15 @@
 #include <mach-o/loader.h>
 #include <mach-o/reloc.h>
 #include <mach-o/nlist.h>
+
+#ifdef HAVE_MACH_O_X86_64_RELOC_H
 #include <mach-o/x86_64/reloc.h>
-#include <mach-o/arm64/reloc.h>
+#endif
 
+// Older versions of Mac OS didn't have this.
+#ifdef HAVE_MACH_O_ARM64_RELOC_H
+#include <mach-o/arm64/reloc.h>
+#endif
 #ifdef HAVE_STRING_H
 #include <string.h>
 #endif