diff --git a/epan/proto.c b/epan/proto.c
index 2f4b033fe0..d873cc4a67 100644
--- a/epan/proto.c
+++ b/epan/proto.c
@@ -304,7 +304,7 @@ static void save_same_name_hfinfo(gpointer data)
 /* Points to the first element of an array of Booleans, indexed by
    a subtree item type; that array element is TRUE if subtrees of
    an item of that type are to be expanded. */
-gboolean	*tree_is_expanded;
+static gboolean	*tree_is_expanded;
 
 /* Number of elements in that array. */
 int		num_tree_types;
@@ -7404,6 +7404,20 @@ proto_check_field_name(const gchar *field_name)
 	return wrs_check_charset(fld_abbrev_chars, field_name);
 }
 
+gboolean
+tree_expanded(int tree_type)
+{
+	g_assert(tree_type >= 0 && tree_type < num_tree_types);
+	return tree_is_expanded[tree_type];
+}
+
+void
+tree_expanded_set(int tree_type, gboolean value)
+{
+	g_assert(tree_type >= 0 && tree_type < num_tree_types);
+	tree_is_expanded[tree_type] = value;
+}
+
 /*
  * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
  *
diff --git a/epan/proto.h b/epan/proto.h
index e82747f9c8..e224364cb0 100644
--- a/epan/proto.h
+++ b/epan/proto.h
@@ -1852,17 +1852,16 @@ WS_DLL_PUBLIC void proto_registrar_dump_fields(void);
 WS_DLL_PUBLIC void proto_registrar_dump_ftypes(void);
 
 
-
-/** Points to the first element of an array of Booleans, indexed by
-   a subtree item type. That array element is TRUE if subtrees of
-   an item of that type are to be expanded. With MSVC and a
-   libwireshark.dll, we need a special declaration. */
-WS_DLL_PUBLIC gboolean	     *tree_is_expanded;
-
 /** Number of elements in the tree_is_expanded array. With MSVC and a
  * libwireshark.dll, we need a special declaration. */
 WS_DLL_PUBLIC int           num_tree_types;
 
+/** Returns TRUE if subtrees of that type are to be expanded. */
+WS_DLL_PUBLIC gboolean tree_expanded(int tree_type);
+
+/** Sets if subtrees of that type are to be expanded. */
+WS_DLL_PUBLIC void tree_expanded_set(int tree_type, gboolean value);
+
 /** glib doesn't have g_ptr_array_len of all things!*/
 #ifndef g_ptr_array_len
 #define g_ptr_array_len(a)      ((a)?(a)->len:0)
diff --git a/print.c b/print.c
index bb4e6911c2..fd6dde9683 100644
--- a/print.c
+++ b/print.c
@@ -238,7 +238,7 @@ void proto_tree_print_node(proto_node *node, gpointer data)
     g_assert((fi->tree_type >= -1) && (fi->tree_type < num_tree_types));
     if ((pdata->print_dissections == print_dissections_expanded) ||
         ((pdata->print_dissections == print_dissections_as_displayed) &&
-         (fi->tree_type >= 0) && tree_is_expanded[fi->tree_type])) {
+         (fi->tree_type >= 0) && tree_expanded(fi->tree_type))) {
         if (node->first_child != NULL) {
             pdata->level++;
             proto_tree_children_foreach(node,
diff --git a/ui/gtk/packet_panes.c b/ui/gtk/packet_panes.c
index ab3a808b0c..15a8ec5736 100644
--- a/ui/gtk/packet_panes.c
+++ b/ui/gtk/packet_panes.c
@@ -214,11 +214,8 @@ expand_tree(GtkTreeView *tree_view, GtkTreeIter *iter,
      * Nodes with "finfo->tree_type" of -1 have no ett_ value, and
      * are thus presumably leaf nodes and cannot be expanded.
      */
-    if (finfo->tree_type != -1) {
-        g_assert(finfo->tree_type >= 0 &&
-                 finfo->tree_type < num_tree_types);
-        tree_is_expanded[finfo->tree_type] = TRUE;
-    }
+    if (finfo->tree_type != -1)
+    	tree_expanded_set(finfo->tree_type, TRUE);
 }
 
 static void
@@ -236,11 +233,8 @@ collapse_tree(GtkTreeView *tree_view, GtkTreeIter *iter,
      * Nodes with "finfo->tree_type" of -1 have no ett_ value, and
      * are thus presumably leaf nodes and cannot be collapsed.
      */
-    if (finfo->tree_type != -1) {
-        g_assert(finfo->tree_type >= 0 &&
-                 finfo->tree_type < num_tree_types);
-        tree_is_expanded[finfo->tree_type] = FALSE;
-    }
+    if (finfo->tree_type != -1)
+    	tree_expanded_set(finfo->tree_type, FALSE);
 }
 
 struct field_lookup_info {
@@ -1288,9 +1282,10 @@ void
 expand_all_tree(proto_tree *protocol_tree _U_, GtkWidget *tree_view)
 {
     int i;
-    for(i=0; i < num_tree_types; i++) {
-        tree_is_expanded[i] = TRUE;
-    }
+
+    for(i=0; i < num_tree_types; i++)
+        tree_expanded_set(i, TRUE);
+
     gtk_tree_view_expand_all(GTK_TREE_VIEW(tree_view));
 }
 
@@ -1298,9 +1293,10 @@ void
 collapse_all_tree(proto_tree *protocol_tree _U_, GtkWidget *tree_view)
 {
     int i;
-    for(i=0; i < num_tree_types; i++) {
-        tree_is_expanded[i] = FALSE;
-    }
+
+    for(i=0; i < num_tree_types; i++)
+        tree_expanded_set(i, FALSE);
+
     gtk_tree_view_collapse_all(GTK_TREE_VIEW(tree_view));
 }
 
@@ -1377,7 +1373,7 @@ expand_finfos(GtkTreeModel *model, GtkTreePath *path, GtkTreeIter *iter, gpointe
 
     g_assert(fi->tree_type >= 0 && fi->tree_type < num_tree_types);
 
-    if (tree_is_expanded[fi->tree_type])
+    if (tree_expanded(fi->tree_type))
         gtk_tree_view_expand_to_path(tree_view, path);
     else
         gtk_tree_view_collapse_row(tree_view, path);
diff --git a/ui/qt/proto_tree.cpp b/ui/qt/proto_tree.cpp
index c63b26a149..1dcec3b5b1 100644
--- a/ui/qt/proto_tree.cpp
+++ b/ui/qt/proto_tree.cpp
@@ -140,7 +140,7 @@ proto_tree_draw_node(proto_node *node, gpointer data)
     }
 
     if (is_branch) {
-        if (tree_is_expanded[fi->tree_type]) {
+        if (tree_expanded(fi->tree_type)) {
             item->setExpanded(true);
         } else {
             item->setExpanded(false);
@@ -334,7 +334,7 @@ void ProtoTree::expand(const QModelIndex & index) {
     if (fi->tree_type != -1) {
         g_assert(fi->tree_type >= 0 &&
                  fi->tree_type < num_tree_types);
-        tree_is_expanded[fi->tree_type] = TRUE;
+        tree_expanded_set(fi->tree_type, TRUE);
     }
 }
 
@@ -351,7 +351,7 @@ void ProtoTree::collapse(const QModelIndex & index) {
     if (fi->tree_type != -1) {
         g_assert(fi->tree_type >= 0 &&
                  fi->tree_type < num_tree_types);
-        tree_is_expanded[fi->tree_type] = FALSE;
+        tree_expanded_set(fi->tree_type, FALSE);
     }
 }
 
@@ -388,7 +388,7 @@ void ProtoTree::expandAll()
 {
     int i;
     for(i=0; i < num_tree_types; i++) {
-        tree_is_expanded[i] = TRUE;
+        tree_expanded_set(i, TRUE);
     }
     QTreeWidget::expandAll();
 }
@@ -397,7 +397,7 @@ void ProtoTree::collapseAll()
 {
     int i;
     for(i=0; i < num_tree_types; i++) {
-        tree_is_expanded[i] = FALSE;
+        tree_expanded_set(i, FALSE);
     }
     QTreeWidget::collapseAll();
 }