diff --git a/cf/db.m4 b/cf/db.m4
index 5c9460f17..789d09c97 100644
--- a/cf/db.m4
+++ b/cf/db.m4
@@ -43,6 +43,7 @@ AS_IF([test "x$with_berkeley_db" != xno],
 		    fi
 		   ])],
     [AC_CHECK_HEADERS([					\
+	           db6/db.h				\
 	           db5/db.h				\
 	           db4/db.h				\
 	           db3/db.h				\