diff --git a/simgear/Makefile.am b/simgear/Makefile.am
index 2dd993de..a3d980a4 100644
--- a/simgear/Makefile.am
+++ b/simgear/Makefile.am
@@ -21,7 +21,8 @@ METAR_DIRS =
 
 EXTRA_DIST = version.h.in
 
-include_HEADERS = compiler.h constants.h fg_traits.hxx fg_zlib.h version.h
+include_HEADERS = \
+	compiler.h constants.h fg_traits.hxx fg_zlib.h inlines.h version.h
 
 SUBDIRS = \
 	bucket \
diff --git a/simgear/constants.h b/simgear/constants.h
index f4d40d2a..d74b2b40 100644
--- a/simgear/constants.h
+++ b/simgear/constants.h
@@ -21,8 +21,8 @@
 // $Id$
 
 
-#ifndef _SUPPORTGEAR_CONSTANTS_H
-#define _SUPPORTGEAR_CONSTANTS_H
+#ifndef _SG_CONSTANTS_H
+#define _SG_CONSTANTS_H
 
 
 #ifdef HAVE_CONFIG_H
@@ -140,4 +140,4 @@
 #define FG_EPSILON 0.0000001
 
 
-#endif // _SUPPORTGEAR_CONSTANTS_H
+#endif // _SG_CONSTANTS_H