diff --git a/compat.h b/compat.h
index 4a7781503..8119c33c9 100644
--- a/compat.h
+++ b/compat.h
@@ -84,6 +84,13 @@
 #  define S_IRWXU		0000700		/* rwx for owner */
 #endif /* S_IRWXU */
 
+/*
+ * Some OS's may not have this.
+ */
+#ifndef howmany
+#define howmany(x, y)	(((x) + ((y) - 1)) / (y))
+#endif
+
 /*
  * We need to know how long the longest password may be.
  * For alternate password schemes we need longer passwords.