diff --git a/CPU.h.in b/CPU.h.in
index 73239ac1589f98595f3dbb3d9b8120f8c8c6b7a6..6b2e49c3ede579028c0ec3a7a90789b9755b7b97 100644
--- a/CPU.h.in
+++ b/CPU.h.in
@@ -32,6 +32,14 @@
 #elif defined(__alpha) || defined(__alpha__) || defined(_M_ALPHA)
 # define @KWSYS_NAMESPACE@_CPU_ENDIAN_ID @KWSYS_NAMESPACE@_CPU_ENDIAN_ID_LITTLE
 
+/* Arm */
+#elif defined(__arm__)
+# if !defined(__ARMEB__)
+#  define @KWSYS_NAMESPACE@_CPU_ENDIAN_ID @KWSYS_NAMESPACE@_CPU_ENDIAN_ID_LITTLE
+# else
+#  define @KWSYS_NAMESPACE@_CPU_ENDIAN_ID @KWSYS_NAMESPACE@_CPU_ENDIAN_ID_BIG
+# endif
+
 /* Intel x86 */
 #elif defined(__i386) || defined(__i386__) || defined(_M_IX86)
 # define @KWSYS_NAMESPACE@_CPU_ENDIAN_ID @KWSYS_NAMESPACE@_CPU_ENDIAN_ID_LITTLE