diff --git a/src/osgProducer/DatabasePager.cpp b/src/osgProducer/DatabasePager.cpp
index 1f852c2d8..75b4a0871 100644
--- a/src/osgProducer/DatabasePager.cpp
+++ b/src/osgProducer/DatabasePager.cpp
@@ -1,6 +1,10 @@
 #include <osgProducer/DatabasePager>
 #include <osgDB/ReadFile>
 
+#ifndef WIN32
+#include <unistd.h>
+#endif
+
 using namespace osgProducer;
 
 DatabasePager::DatabasePager()