diff --git a/poppler/StructElement.cc b/poppler/StructElement.cc
index 0fbd336..6ddc228 100644
--- a/poppler/StructElement.cc
+++ b/poppler/StructElement.cc
@@ -248,6 +248,7 @@ struct AttributeMapEntry {
 };

 struct AttributeDefaults {
+  AttributeDefaults(){}
   Object Inline  = Object(objName, "Inline");
   Object LrTb = Object(objName, "LrTb");
   Object Normal = Object(objName, "Normal");