diff --git a/modules/contrib/biblio/modules/CiteProc/style/chicago-author-date.csl b/modules/contrib/biblio/modules/CiteProc/style/chicago-author-date.csl
index 5921820..7735f8b 100644
--- a/modules/contrib/biblio/modules/CiteProc/style/chicago-author-date.csl
+++ b/modules/contrib/biblio/modules/CiteProc/style/chicago-author-date.csl
@@ -42,7 +42,7 @@
    <macro name="container-contributors">
       <choose>
          <if type="chapter paper-conference" match="any">
-            <group prefix="," delimiter=", ">
+            <group prefix=", " delimiter=", ">
                <choose>
                   <if variable="author">
                      <names variable="editor">