diff --git a/includes/functions.php b/includes/functions.php
index 5730b7b44b..a038bab960 100644
--- a/includes/functions.php
+++ b/includes/functions.php
@@ -1624,6 +1624,12 @@ function q_bridge_bits2indices($hex_data)
      * ie. '9a00' -> '100110100000' -> array(1, 4, 5, 7)
     */
     $hex_data = str_replace(' ', '', $hex_data);
+
+    // we need an even number of digits for hex2bin
+    if (strlen($hex_data) % 2 === 1) {
+        $hex_data = '0' . $hex_data;
+    }
+
     $value = hex2bin($hex_data);
     $length = strlen($value);
     $indices = [];