diff --git a/ui/qt/proto_tree.cpp b/ui/qt/proto_tree.cpp
index c97a172d96..e333926d43 100644
--- a/ui/qt/proto_tree.cpp
+++ b/ui/qt/proto_tree.cpp
@@ -184,8 +184,9 @@ void ProtoTree::contextMenuEvent(QContextMenuEvent *event)
     // The "text only" header field will not give preferences for the selected protocol.
     // Use parent in this case.
     proto_node *node = proto_tree_model_->protoNodeFromIndex(index).protoNode();
-    while (node && node->finfo->hfinfo->id == hf_text_only)
+    while (node && node->finfo && node->finfo->hfinfo && node->finfo->hfinfo->id == hf_text_only)
         node = node->parent;
+
     FieldInformation pref_finfo(node);
     proto_prefs_menu_.setModule(pref_finfo.moduleName());
 
diff --git a/ui/qt/utils/field_information.cpp b/ui/qt/utils/field_information.cpp
index d671106cf7..876f8bdb6f 100644
--- a/ui/qt/utils/field_information.cpp
+++ b/ui/qt/utils/field_information.cpp
@@ -15,7 +15,7 @@ FieldInformation::FieldInformation(field_info *fi, QObject * parent)
 :QObject(parent)
 {
     fi_ = fi;
-    parent_fi_ = 0;
+    parent_fi_ = NULL;
 }
 
 FieldInformation::FieldInformation(proto_node *node, QObject * parent)
@@ -34,7 +34,7 @@ bool FieldInformation::isValid() const
 
     if ( fi_ && fi_->hfinfo )
     {
-        if (fi_->hfinfo->blurb != 0 && fi_->hfinfo->blurb[0] != '\0') {
+        if (fi_->hfinfo->blurb != NULL && fi_->hfinfo->blurb[0] != '\0') {
             ret = true;
         } else {
             ret = QString((fi_->hfinfo->name)).length() > 0;