diff --git a/include/missing.h b/include/missing.h
index a060b7cc8..8276065cf 100644
--- a/include/missing.h
+++ b/include/missing.h
@@ -149,6 +149,13 @@
 # define MAX(a,b) (((a)>(b))?(a):(b))
 #endif
 
+/*
+ * Some systems define this in <sys/param.h> but we don't include that anymore.
+ */
+#ifndef howmany
+# define howmany(x, y)	(((x) + ((y) - 1)) / (y))
+#endif
+
 /*
  * Older systems may be missing stddef.h and/or offsetof macro
  */