diff --git a/help.c b/help.c
index 5061c48..d0da9f8 100644
--- a/help.c
+++ b/help.c
@@ -5658,7 +5658,7 @@ NULL
 char *help_tree[] = {
 "tree",
 "display radix tree or red-black tree",
-"-t [radix|rbtree] [-r offset] [-[s|S] struct[.member[,member]] -[x|d]]\n          [-o offset] [-p] [-l] [-N] start",
+"[-t [radix|rbtree]] [-r offset] [-[s|S] struct[.member[,member]]] -[x|d]\n       [-o offset] [-l] [-p] [-N] start",
 "  This command dumps the contents of a radix tree or a red-black tree.",
 "  The arguments are as follows:\n",
 "    -t type  The type of tree to dump; the type string can be either ",
@@ -5691,15 +5691,16 @@ char *help_tree[] = {
 "  -S struct  Similar to -s, but instead of parsing gdb output, member values",
 "             are read directly from memory, so the command works much faster", 
 "             for 1-, 2-, 4-, and 8-byte members.",
-"         -x  Override default output format with hexadecimal format.",
-"         -d  Override default output format with decimal format.",
+"         -l  For red-black trees, dump the tree sorted in linear order starting",
+"             with the leftmost node and progressing to the right.  This option",
+"             does not apply to radix trees.",
 "         -p  Display the node's position information, showing the relationship",
 "             between it and the root.  For red-black trees, a position that",
 "             indicates \"root/l/r\" means that the node is the right child",
 "             of the left child of the root node.  For radix trees, the height",
 "             and slot index values are shown with respect to the root.",
-"         -l  Dump the tree sorted in linear order starting with the leftmost",
-"             node and progressing to the right.",
+"         -x  Override default output format with hexadecimal format.",
+"         -d  Override default output format with decimal format.",
 " ",
 "  The meaning of the \"start\" argument, which can be expressed either in",
 "  hexadecimal format or symbolically, depends upon whether the -N option",
diff --git a/tools.c b/tools.c
index cd89471..1a83643 100644
--- a/tools.c
+++ b/tools.c
@@ -3946,6 +3946,10 @@ cmd_tree()
 				
 			break;
 
+		case 'l':
+			td->flags |= TREE_LINEAR_ORDER;
+			break;
+
 		case 'r':
 			if (td->flags & TREE_ROOT_OFFSET_ENTERED) 
 				error(FATAL,
@@ -3993,10 +3997,6 @@ cmd_tree()
 			td->flags |= TREE_POSITION_DISPLAY;
 			break;
 
-		case 'l':
-			td->flags |= TREE_LINEAR_ORDER;
-			break;
-
 		case 'N':
 			td->flags |= TREE_NODE_POINTER;
 			break;
@@ -4023,12 +4023,15 @@ cmd_tree()
 	if (argerrs)
 		cmd_usage(pc->curcmd, SYNOPSIS);
 
+	if ((type_flag & RADIXTREE_REQUEST) && (td->flags & TREE_LINEAR_ORDER))
+		error(FATAL, "-l option is not applicable to radix trees\n");
+
 	if ((type_flag & RADIXTREE_REQUEST) && (td->flags & TREE_NODE_OFFSET_ENTERED))
 		error(FATAL, "-o option is not applicable to radix trees\n");
 
 	if ((td->flags & TREE_ROOT_OFFSET_ENTERED) && 
 	    (td->flags & TREE_NODE_POINTER))
-		error(INFO, "-r and -N options are mutually exclusive\n");
+		error(FATAL, "-r and -N options are mutually exclusive\n");
 
 	if (!args[optind]) {
 		error(INFO, "a starting address is required\n");