diff --git a/epan/proto.c b/epan/proto.c
index d6eac59785..7d24c0e3d6 100644
--- a/epan/proto.c
+++ b/epan/proto.c
@@ -280,8 +280,7 @@ struct _protocol {
 	const char *name;         /* long description */
 	const char *short_name;   /* short description */
 	const char *filter_name;  /* name of this protocol in filters */
-	GSList     *fields;       /* fields for this protocol */
-	GSList     *last_field;   /* pointer to end of list of fields */
+	GPtrArray  *fields;       /* fields for this protocol */
 	int         proto_id;     /* field ID for this protocol */
 	gboolean    is_enabled;   /* TRUE if protocol is enabled */
 	gboolean    can_toggle;   /* TRUE if is_enabled can be changed */
@@ -534,7 +533,7 @@ proto_cleanup(void)
 		DISSECTOR_ASSERT(protocol->proto_id == hfinfo->id);
 
 		g_slice_free(header_field_info, hfinfo);
-		g_slist_free(protocol->fields);
+		g_ptr_array_free(protocol->fields, TRUE);
 		protocols = g_list_remove(protocols, protocol);
 		g_free(protocol);
 	}
@@ -4825,7 +4824,7 @@ proto_register_protocol(const char *name, const char *short_name,
 	protocol->name = name;
 	protocol->short_name = short_name;
 	protocol->filter_name = filter_name;
-	protocol->fields = NULL;
+	protocol->fields = g_ptr_array_new();
 	protocol->is_enabled = TRUE; /* protocol is enabled by default */
 	protocol->can_toggle = TRUE;
 	protocol->is_private = FALSE;
@@ -4913,26 +4912,28 @@ proto_get_next_protocol(void **cookie)
 header_field_info *
 proto_get_first_protocol_field(const int proto_id, void **cookie)
 {
-	protocol_t       *protocol = find_protocol_by_id(proto_id);
+	protocol_t *protocol = find_protocol_by_id(proto_id);
 
-	if ((protocol == NULL) || (protocol->fields == NULL))
+	if ((protocol == NULL) || (protocol->fields->len == 0))
 		return NULL;
 
-	*cookie = protocol->fields;
-	return (header_field_info *)protocol->fields->data;
+	*cookie = GINT_TO_POINTER(0);
+	return (header_field_info *)g_ptr_array_index(protocol->fields, 0);
 }
 
 header_field_info *
-proto_get_next_protocol_field(void **cookie)
+proto_get_next_protocol_field(const int proto_id, void **cookie)
 {
-	GSList           *list_item = (GSList *)*cookie;
+	protocol_t *protocol = find_protocol_by_id(proto_id);
+	guint       index    = GPOINTER_TO_INT(*cookie);
 
-	list_item = g_slist_next(list_item);
-	if (list_item == NULL)
+	index++;
+
+	if (index >= protocol->fields->len)
 		return NULL;
 
-	*cookie = list_item;
-	return (header_field_info *)list_item->data;
+	*cookie = GINT_TO_POINTER(index);
+	return (header_field_info *)g_ptr_array_index(protocol->fields, index);
 }
 
 protocol_t *
@@ -5096,13 +5097,7 @@ static int
 proto_register_field_common(protocol_t *proto, header_field_info *hfi, const int parent)
 {
 	if (proto != NULL) {
-		if (proto->fields == NULL) {
-			proto->fields = g_slist_append(NULL, hfi);
-			proto->last_field = proto->fields;
-		} else {
-			proto->last_field =
-				g_slist_append(proto->last_field, hfi)->next;
-		}
+		g_ptr_array_add(proto->fields, hfi);
 	}
 
 	return proto_register_field_init(hfi, parent);
@@ -5188,25 +5183,23 @@ proto_unregister_field (const int parent, gint hf_id)
 {
 	hf_register_info *hf;
 	protocol_t       *proto;
-	GSList           *field;
+	guint             i;
 
 	if (hf_id == -1 || hf_id == 0)
 		return;
 
 	proto = find_protocol_by_id (parent);
-	if (!proto || !proto->fields) {
+	if (!proto || proto->fields->len == 0) {
 		return;
 	}
 
-	for (field = proto->fields; field; field = field->next) {
-		hf = (hf_register_info *)field->data;
+	for (i = 0; i < proto->fields->len; i++) {
+		hf = (hf_register_info *)g_ptr_array_index(proto->fields, i);
 		if (*hf->p_id == hf_id) {
 			/* Found the hf_id in this protocol */
 			g_hash_table_steal(gpa_name_map, hf->hfinfo.abbrev);
-			/* XXX, memleak? g_slist_delete_link() */
-			proto->fields = g_slist_remove_link (proto->fields, field);
-			proto->last_field = g_slist_last (proto->fields);
-			break;
+			g_ptr_array_remove_index_fast(proto->fields, i);
+			return;
 		}
 	}
 }
diff --git a/epan/proto.h b/epan/proto.h
index eac413478a..f3f34995d3 100644
--- a/epan/proto.h
+++ b/epan/proto.h
@@ -1900,8 +1900,8 @@ extern gint proto_registrar_get_length(const int n);
 WS_DLL_PUBLIC int proto_get_first_protocol(void **cookie);
 WS_DLL_PUBLIC int proto_get_data_protocol(void *cookie);
 WS_DLL_PUBLIC int proto_get_next_protocol(void **cookie);
-WS_DLL_PUBLIC header_field_info *proto_get_first_protocol_field(const int proto_id, void **cookle);
-WS_DLL_PUBLIC header_field_info *proto_get_next_protocol_field(void **cookle);
+WS_DLL_PUBLIC header_field_info *proto_get_first_protocol_field(const int proto_id, void **cookie);
+WS_DLL_PUBLIC header_field_info *proto_get_next_protocol_field(const int proto_id, void **cookie);
 
 /** Given a protocol's filter_name.
  @param filter_name the filter name to search for
diff --git a/epan/wslua/wslua_field.c b/epan/wslua/wslua_field.c
index 72dc551d7f..6693ea1489 100644
--- a/epan/wslua/wslua_field.c
+++ b/epan/wslua/wslua_field.c
@@ -538,7 +538,7 @@ WSLUA_CONSTRUCTOR Field_list(lua_State *L) {
          i = proto_get_next_protocol(&cookie)) {
 
         for (hfinfo = proto_get_first_protocol_field(i, &cookie2); hfinfo != NULL;
-         hfinfo = proto_get_next_protocol_field(&cookie2)) {
+         hfinfo = proto_get_next_protocol_field(i, &cookie2)) {
 
             if (hfinfo->same_name_prev_id != -1) /* ignore duplicate names */
                 continue;
diff --git a/ui/gtk/filter_autocomplete.c b/ui/gtk/filter_autocomplete.c
index 3978bc04e3..91048aa052 100644
--- a/ui/gtk/filter_autocomplete.c
+++ b/ui/gtk/filter_autocomplete.c
@@ -657,7 +657,7 @@ build_autocompletion_list(GtkWidget *filter_te, GtkWidget *treeview, GtkWidget *
 
       for (hfinfo = proto_get_first_protocol_field(i, &cookie2);
            hfinfo != NULL;
-           hfinfo = proto_get_next_protocol_field(&cookie2))
+           hfinfo = proto_get_next_protocol_field(i, &cookie2))
       {
         if (hfinfo->same_name_prev_id != -1) /* ignore duplicate names */
           continue;
diff --git a/ui/gtk/proto_hier_tree_model.c b/ui/gtk/proto_hier_tree_model.c
index 6ae13f610d..5ba701f82f 100644
--- a/ui/gtk/proto_hier_tree_model.c
+++ b/ui/gtk/proto_hier_tree_model.c
@@ -98,7 +98,7 @@ proto_hier_tree_iter_nth_child(GtkTreeModel *tree_model, GtkTreeIter *iter, GtkT
 					break;
 				n--;
 			}
-			hfinfo = proto_get_next_protocol_field(&cookie);
+			hfinfo = proto_get_next_protocol_field(proto_id, &cookie);
 		}
 
 		/* not found? */
@@ -238,13 +238,14 @@ proto_hier_tree_iter_next(GtkTreeModel *tree_model, GtkTreeIter *iter)
 	{
 		void *cookie2 = iter->user_data2;
 		header_field_info *hfinfo;
+		int proto_id = proto_get_data_protocol(iter->user_data);
 
-		hfinfo = proto_get_next_protocol_field(&cookie2);
+		hfinfo = proto_get_next_protocol_field(proto_id, &cookie2);
 		/* get next field */
 		while (hfinfo) {
 			if (hfinfo->same_name_prev_id == -1)
 				break;
-			hfinfo = proto_get_next_protocol_field(&cookie2);
+			hfinfo = proto_get_next_protocol_field(proto_id, &cookie2);
 		}
 
 		/* not found? */
@@ -289,7 +290,7 @@ proto_hier_tree_iter_n_children(GtkTreeModel *tree_model, GtkTreeIter *iter)
 		p_id = proto_get_data_protocol(iter->user_data);
 
 		/* count not-duplicated fields */
-		for (hfinfo = proto_get_first_protocol_field(p_id, &cookie); hfinfo; hfinfo = proto_get_next_protocol_field(&cookie)) {
+		for (hfinfo = proto_get_first_protocol_field(p_id, &cookie); hfinfo; hfinfo = proto_get_next_protocol_field(p_id, &cookie)) {
 			if (hfinfo->same_name_prev_id != -1)
 				continue;
 			count++;
@@ -350,7 +351,7 @@ proto_hier_tree_get_path(GtkTreeModel *tree_model, GtkTreeIter *iter)
 		header_field_info *hfinfo;
 
 		pos = 0;
-		for (hfinfo = proto_get_first_protocol_field(p_id, &cookie); hfinfo && hfinfo != iter->user_data3; hfinfo = proto_get_next_protocol_field(&cookie)) {
+		for (hfinfo = proto_get_first_protocol_field(p_id, &cookie); hfinfo && hfinfo != iter->user_data3; hfinfo = proto_get_next_protocol_field(p_id, &cookie)) {
 			if (hfinfo->same_name_prev_id != -1)
 				continue;
 			pos++;
diff --git a/ui/gtk/supported_protos_dlg.c b/ui/gtk/supported_protos_dlg.c
index ffb7c20d68..4609bd1e91 100644
--- a/ui/gtk/supported_protos_dlg.c
+++ b/ui/gtk/supported_protos_dlg.c
@@ -255,7 +255,7 @@ static void set_supported_text(GtkWidget *w, supported_type_t type)
          i = proto_get_next_protocol(&cookie)) {
 
 	    for (hfinfo = proto_get_first_protocol_field(i, &cookie2); hfinfo != NULL;
-		 hfinfo = proto_get_next_protocol_field(&cookie2)) {
+		 hfinfo = proto_get_next_protocol_field(i, &cookie2)) {
 
 		    if (hfinfo->same_name_prev_id != -1) /* ignore duplicate names */
 			    continue;
@@ -283,7 +283,7 @@ static void set_supported_text(GtkWidget *w, supported_type_t type)
 
 	    count = 0;
 	    for (hfinfo = proto_get_first_protocol_field(i, &cookie2); hfinfo != NULL;
-		 hfinfo = proto_get_next_protocol_field(&cookie2)) {
+		 hfinfo = proto_get_next_protocol_field(i, &cookie2)) {
 
 		    if (hfinfo->same_name_prev_id != -1) /* ignore duplicate names */
 			    continue;
@@ -296,7 +296,7 @@ static void set_supported_text(GtkWidget *w, supported_type_t type)
 	    insert_text(w, buffer, len);
 
 	    for (hfinfo = proto_get_first_protocol_field(i, &cookie2); hfinfo != NULL;
-		 hfinfo = proto_get_next_protocol_field(&cookie2)) {
+		 hfinfo = proto_get_next_protocol_field(i, &cookie2)) {
 
 		    if (hfinfo->same_name_prev_id != -1) /* ignore duplicate names */
 			    continue;