diff --git a/compiler/utils/arm/constants_arm.h b/compiler/utils/arm/constants_arm.h
index 092c891..702e03a 100644
--- a/compiler/utils/arm/constants_arm.h
+++ b/compiler/utils/arm/constants_arm.h
@@ -47,6 +47,16 @@
 #error "Exactly one of VFPv3_D16 or VFPv3_D32 can be defined at a time."
 #endif
 
+// 4 bits option for the dmb instruction.
+// Order and values follows those of the ARM Architecture Reference Manual.
+enum DmbOptions {
+  SY = 0xf,
+  ST = 0xe,
+  ISH = 0xb,
+  ISHST = 0xa,
+  NSH = 0x7,
+  NSHST = 0x6
+};
 
 enum ScaleFactor {
   TIMES_1 = 0,