diff --git a/publi_bib.php b/publi_bib.php
index e1a9231..7a5fe53 100644
--- a/publi_bib.php
+++ b/publi_bib.php
@@ -142,7 +142,10 @@ function convertFirstNameToInitial($name) {
         if (strpos($part, '-') !== false) {
             $hyphenParts = explode('-', $part);
             $initials = array_map(function($p) {
-                return ucfirst($p[0]) . '.';
+                if (!empty($p)) {
+                  return ucfirst($p[0]) . '.';
+                }
+                return '';
             }, $hyphenParts);
             return implode('-', $initials);
         }