diff --git a/compiler/utils/arm/constants_arm.h b/compiler/utils/arm/constants_arm.h
index 6b4daed..2060064 100644
--- a/compiler/utils/arm/constants_arm.h
+++ b/compiler/utils/arm/constants_arm.h
@@ -148,7 +148,8 @@
   MOV = 13,  // Move
   BIC = 14,  // Bit Clear
   MVN = 15,  // Move Not
-  kMaxOperand = 16
+  ORN = 16,  // Logical OR NOT.
+  kMaxOperand = 17
 };
 std::ostream& operator<<(std::ostream& os, const Opcode& rhs);