diff --git a/lib/Kconfig b/lib/Kconfig
index 8ade0a7..9960be0 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -10,6 +10,9 @@
 config BITREVERSE
 	tristate
 
+config RATIONAL
+	boolean
+
 config GENERIC_FIND_FIRST_BIT
 	bool