diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c854a3e6c5b..44fac540afd 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2016-05-17  James Greenhalgh  <james.greenhalgh@arm.com>
+
+	* config/aarch64/aarch64.c
+	(aarch64_output_simd_mov_immediate): Make "buf_size" a variable
+	rather than a macro.
+
 2016-05-16  Wilco Dijkstra  <wdijkstr@arm.com>
 
         * doc/invoke.texi (AArch64 Options): Various updates.
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index e081b16f324..986262b91ef 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -11845,12 +11845,11 @@ aarch64_output_simd_mov_immediate (rtx const_vector,
         info.value = GEN_INT (0);
       else
 	{
-#define buf_size 20
+	  const unsigned int buf_size = 20;
 	  char float_buf[buf_size] = {'\0'};
 	  real_to_decimal_for_mode (float_buf,
 				    CONST_DOUBLE_REAL_VALUE (info.value),
 				    buf_size, buf_size, 1, mode);
-#undef buf_size
 
 	  if (lane_count == 1)
 	    snprintf (templ, sizeof (templ), "fmov\t%%d0, %s", float_buf);