diff --git a/src/include/config-aux.h b/src/include/config-aux.h
index 4bf3120..629e077 100644
--- a/src/include/config-aux.h
+++ b/src/include/config-aux.h
@@ -26,7 +26,6 @@
 #endif
 
 /* Boolean type support */
-#undef HAVE_STDBOOL_H
 #ifdef HAVE_STDBOOL_H
 # include <stdbool.h>
 #else