diff --git a/ChangeLog b/ChangeLog
index 04d41b34..3ff7b476 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2008-05-25  Nicolas François  <nicolas.francois@centraliens.net>
+
+	* configure.in, lib/defines.h: Allow usage of booleans in the
+	source.
+
 2008-05-25  Nicolas François  <nicolas.francois@centraliens.net>
 
 	* configure.in: Allow --disable-man and --enable-man=no.
diff --git a/lib/defines.h b/lib/defines.h
index a3ab5aaf..e946109e 100644
--- a/lib/defines.h
+++ b/lib/defines.h
@@ -321,4 +321,20 @@ extern char *strerror ();
 # define unused
 #endif
 
+#if HAVE_STDBOOL_H
+# include <stdbool.h>
+#else
+# if ! HAVE__BOOL
+#  ifdef __cplusplus
+typedef bool _Bool;
+#  else
+typedef unsigned char _Bool;
+#  endif
+# endif
+# define bool _Bool
+# define false 0
+# define true 1
+# define __bool_true_false_are_defined 1
+#endif
+
 #endif				/* _DEFINES_H_ */