diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index 61572ddd297..4414037ee68 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,3 +1,8 @@
+2017-08-07  H.J. Lu  <hongjiu.lu@intel.com>
+
+	* disassemble.c (disassembler): Mark big and mach with
+	ATTRIBUTE_UNUSED.
+
 2017-08-07  Maciej W. Rozycki  <macro@imgtec.com>
 
 	* disassemble.c (disassembler): Remove arch/mach/endian
diff --git a/opcodes/disassemble.c b/opcodes/disassemble.c
index 00583542655..11206c67a5f 100644
--- a/opcodes/disassemble.c
+++ b/opcodes/disassemble.c
@@ -110,7 +110,9 @@
 #endif
 
 disassembler_ftype
-disassembler (enum bfd_architecture a, bfd_boolean big, unsigned long mach,
+disassembler (enum bfd_architecture a,
+	      bfd_boolean big ATTRIBUTE_UNUSED,
+	      unsigned long mach ATTRIBUTE_UNUSED,
 	      bfd *abfd ATTRIBUTE_UNUSED)
 {
   disassembler_ftype disassemble;