diff --git a/_layouts/bib.liquid b/_layouts/bib.liquid
index a4c693f..db179fd 100644
--- a/_layouts/bib.liquid
+++ b/_layouts/bib.liquid
@@ -160,9 +160,11 @@
     {% else %}
       {% capture entrytype %}{% endcapture %}
     {% endif %}
+    {% assign entrymonth = '' %}
     {% if entry.month %}
       {% capture entrymonth %}{{ " " }}{{ entry.month | capitalize }}{% endcapture %}
     {% endif %}
+    {% assign entryyear = '' %}
     {% if entry.year %}
       {% capture entryyear %}{{ " " }}{{ entry.year }}{% endcapture %}
     {% endif %}