diff --git a/srcpkgs/chmlib/patches/arm-64.patch b/srcpkgs/chmlib/patches/arm-64.patch
new file mode 100644
index 00000000000..8c5a9c18160
--- /dev/null
+++ b/srcpkgs/chmlib/patches/arm-64.patch
@@ -0,0 +1,11 @@
+--- src/chm_lib.c	2017-07-07 20:15:32.999769723 +0200
++++ src/chm_lib.c	2017-07-07 20:16:22.291847266 +0200
+@@ -164,7 +164,7 @@
+ 
+ /* x86-64 */
+ /* Note that these may be appropriate for other 64-bit machines. */
+-#elif __x86_64__ || __ia64__
++#elif __x86_64__ || __ia64__ || __aarch64__
+ typedef unsigned char           UChar;
+ typedef short                   Int16;
+ typedef unsigned short          UInt16;