diff --git a/thermosphere/src/my_libc.c b/thermosphere/src/my_libc.c
index 24e3a1b3e..a6f0a2077 100644
--- a/thermosphere/src/my_libc.c
+++ b/thermosphere/src/my_libc.c
@@ -730,6 +730,11 @@ QUICKREF
 /*SUPPRESS 560*/
 /*SUPPRESS 530*/
 
+/* Nonzero if X is aligned on a "long" boundary.  */
+#define ALIGNED(X) \
+  (((long)X & (sizeof (long) - 1)) == 0)
+
+
 char *
 strcat (char *s1, const char *s2)
 {