diff --git a/simgear/sg_zlib.h b/simgear/sg_zlib.h
index f39d5593..57be1fd9 100644
--- a/simgear/sg_zlib.h
+++ b/simgear/sg_zlib.h
@@ -35,8 +35,12 @@
 
 
 #ifdef HAVE_CONFIG_H
+#ifdef FGFS
+#  include <config.h>
+#else
 #  include <simgear_config.h>
 #endif
+#endif
 
 
 #ifdef AVOID_USING_ZLIB