diff --git a/include/nuttx/compiler.h b/include/nuttx/compiler.h
index 2c93231439..20709674b8 100644
--- a/include/nuttx/compiler.h
+++ b/include/nuttx/compiler.h
@@ -576,7 +576,9 @@
 
 /* Indicate that a local variable is not used */
 
-#  define UNUSED(a) ((void)(1 || &(a)))
+#  ifndef UNUSED
+#    define UNUSED(a) ((void)(1 || &(a)))
+#  endif
 
 #  if defined(__clang__)
 #    define no_builtin(n) __attribute__((no_builtin(n)))
@@ -708,7 +710,9 @@
 
 /* Indicate that a local variable is not used */
 
-#  define UNUSED(a) ((void)(1 || &(a)))
+#  ifndef UNUSED
+#    define UNUSED(a) ((void)(1 || &(a)))
+#  endif
 
 /* It is assumed that the system is build using the small
  * data model with storage defaulting to internal RAM.
@@ -901,7 +905,9 @@
 
 /* Indicate that a local variable is not used */
 
-#  define UNUSED(a) ((void)(1 || &(a)))
+#  ifndef UNUSED
+#    define UNUSED(a) ((void)(1 || &(a)))
+#  endif
 
 /* Older Zilog compilers support both types double and long long, but the
  * size is 32-bits (same as long and single precision) so it is safer to say
@@ -992,7 +998,9 @@
 
 /* Indicate that a local variable is not used */
 
-#  define UNUSED(a) ((void)(1 || &(a)))
+#  ifndef UNUSED
+#    define UNUSED(a) ((void)(1 || &(a)))
+#  endif
 
 #  define CONFIG_CPP_HAVE_VARARGS 1 /* Supports variable argument macros */
 #  define CONFIG_HAVE_FILENAME 1    /* Has __FILE__ */
@@ -1088,7 +1096,9 @@
 #  undef  CONFIG_LONG_IS_NOT_INT
 #  undef  CONFIG_PTR_IS_NOT_INT
 
-#  define UNUSED(a) ((void)(1 || &(a)))
+#  ifndef UNUSED
+#    define UNUSED(a) ((void)(1 || &(a)))
+#  endif
 
 #  define offsetof(a, b) ((size_t)(&(((a *)(0))->b)))
 #  define return_address(x) 0
@@ -1179,7 +1189,9 @@
 #  undef  CONFIG_LONG_IS_NOT_INT
 #  undef  CONFIG_PTR_IS_NOT_INT
 
-#  define UNUSED(a) ((void)(1 || &(a)))
+#  ifndef UNUSED
+#    define UNUSED(a) ((void)(1 || &(a)))
+#  endif
 
 #  define offsetof(a, b) ((size_t)(&(((a *)(0))->b)))
 #  define return_address(x) 0
@@ -1261,7 +1273,9 @@
 #  undef  CONFIG_HAVE_DOUBLE
 #  undef  CONFIG_HAVE_LONG_DOUBLE
 
-#  define UNUSED(a) ((void)(1 || &(a)))
+#  ifndef UNUSED
+#    define UNUSED(a) ((void)(1 || &(a)))
+#  endif
 
 #  define offsetof(a, b) ((size_t)(&(((a *)(0))->b)))
 #  define return_address(x) 0