diff -uNr celestia-1.6.1/src/celengine/frametree.h celestia-1.6.1p/src/celengine/frametree.h
--- celestia-1.6.1/src/celengine/frametree.h	2012-07-30 17:53:15.238932943 +0300
+++ celestia-1.6.1p/src/celengine/frametree.h	2012-07-30 17:53:47.080422007 +0300
@@ -13,6 +13,7 @@
 #ifndef _CELENGINE_FRAMETREE_H_
 #define _CELENGINE_FRAMETREE_H_
 
+#include <unistd.h>
 #include <vector>
 #include <cstdio>
 
diff -uNr celestia-1.6.1/src/celengine/planetgrid.cpp celestia-1.6.1p/src/celengine/planetgrid.cpp
--- celestia-1.6.1/src/celengine/planetgrid.cpp	2011-06-05 19:11:09.000000000 +0300
+++ celestia-1.6.1p/src/celengine/planetgrid.cpp	2012-07-30 17:54:02.946665713 +0300
@@ -12,6 +12,7 @@
 
 #include <cstdio>
 #include <cmath>
+#include <celmath/mathlib.h>
 #include <celmath/intersect.h>
 #include "planetgrid.h"
 #include "body.h"