diff --git a/navigationtabstrip/src/main/res/values/attrs.xml b/navigationtabstrip/src/main/res/values/attrs.xml
index c5df4b6..d837938 100644
--- a/navigationtabstrip/src/main/res/values/attrs.xml
+++ b/navigationtabstrip/src/main/res/values/attrs.xml
@@ -7,7 +7,7 @@
         <attr name="nts_weight" format="dimension"/>
         <attr name="nts_factor" format="float"/>
         <attr name="nts_titles" format="reference"/>
-        <attr name="nts_bold" value="true"/>
+        <attr name="nts_bold" format="boolean" value="true"/>
 
         <attr name="nts_type" format="enum">
             <enum name="line" value="0"/>