diff --git a/art/demo.ecotex b/art/demo.ecotex
index 3eeb349..683a36b 100644
Binary files a/art/demo.ecotex and b/art/demo.ecotex differ
diff --git a/art/test.ecotex b/art/test.ecotex
index 346ae00..14753c6 100644
Binary files a/art/test.ecotex and b/art/test.ecotex differ
diff --git a/code/game/source/editors/texed_prj.c b/code/game/source/editors/texed_prj.c
index 4cc5e07..fd83ff4 100644
--- a/code/game/source/editors/texed_prj.c
+++ b/code/game/source/editors/texed_prj.c
@@ -1,7 +1,7 @@
 
 //~ NOTE(zaklaus): DATA SERIALISATION
 
-#define ECOTEX_VERSION 2
+#define ECOTEX_VERSION 3
 
 #define UNPACK(kind) cw_unpack_next(&uc); assert(uc.item.type == kind);
 
@@ -34,6 +34,8 @@ void texed_load(void) {
         texed_add_op(kind);
         td_op *op = zpl_array_end(ctx.ops);
         UNPACK(CWP_ITEM_BOOLEAN);
+        op->is_locked = uc.item.as.boolean;
+        UNPACK(CWP_ITEM_BOOLEAN);
         op->is_hidden = uc.item.as.boolean;
         
         UNPACK(CWP_ITEM_ARRAY);
@@ -86,6 +88,7 @@ void texed_save(void) {
     for (int i = 0; i < zpl_array_count(ctx.ops); i += 1) {
         td_op *op = &ctx.ops[i];
         cw_pack_unsigned(&pc, op->kind);
+        cw_pack_boolean(&pc, (bool)op->is_locked);
         cw_pack_boolean(&pc, (bool)op->is_hidden);
         cw_pack_array_size(&pc, op->num_params);
         for (int j = 0; j < op->num_params; j += 1) {
diff --git a/code/game/source/editors/texed_widgets.c b/code/game/source/editors/texed_widgets.c
index 802b8f7..883b7cf 100644
--- a/code/game/source/editors/texed_widgets.c
+++ b/code/game/source/editors/texed_widgets.c
@@ -74,7 +74,7 @@ void texed_draw_topbar(zpl_aabb2 r) {
 }
 
 static bool is_add_op_dropbox_open = false;
-static int add_op_dropbox_selected = 1;
+static int add_op_dropbox_selected = 0;
 static char add_op_list[2000] = {0};
 
 void texed_draw_oplist_pane(zpl_aabb2 r) {
@@ -145,6 +145,7 @@ void texed_draw_oplist_pane(zpl_aabb2 r) {
         
         zpl_aabb2 hidden_r = zpl_aabb2_cut_right(&op_item_r, 60.0f);
         
+        if (!default_ops[ctx.ops[i].kind].is_locked) GuiSetState(GUI_STATE_NORMAL);
         if (GuiButton(aabb2_ray(hidden_r), ctx.ops[i].is_hidden ? "SHOW" : "HIDE")) {
             ctx.ops[i].is_hidden = !ctx.ops[i].is_hidden;
             texed_repaint_preview();
@@ -159,6 +160,14 @@ void texed_draw_oplist_pane(zpl_aabb2 r) {
         }
         GuiSetState(GUI_STATE_NORMAL);
         
+        zpl_aabb2 lock_r = zpl_aabb2_cut_right(&op_item_r, 20.0f);
+        
+        if (default_ops[ctx.ops[i].kind].is_locked) GuiSetState(GUI_STATE_DISABLED);
+        if (GuiButton(aabb2_ray(lock_r), ctx.ops[i].is_locked ? "#138#" : "#137#")) {
+            ctx.ops[i].is_locked = !ctx.ops[i].is_locked;
+        }
+        GuiSetState(GUI_STATE_NORMAL);
+        
         GuiDrawText(zpl_bprintf("%s %s", ctx.ops[i].name, ctx.ops[i].is_locked ? "(locked)" : ""), GetTextBounds(LABEL, list_text), GuiGetStyle(LABEL, TEXT_ALIGNMENT), Fade(RAYWHITE, guiAlpha));
     }
     
@@ -167,7 +176,15 @@ void texed_draw_oplist_pane(zpl_aabb2 r) {
     if (is_add_op_dropbox_open && (op_dropdown_state = GuiDropdownBoxEco(aabb2_ray(add_op_r), add_op_list, "ADD OPERATION", &add_op_dropbox_selected, true)) > 0) {
         is_add_op_dropbox_open = false;
         if (op_dropdown_state < 2) {
-            texed_add_op(add_op_dropbox_selected);
+            int idx = 0;
+            for (int i = 0; i < DEF_OPS_LEN; i += 1) {
+                if (!default_ops[i].is_locked && idx == add_op_dropbox_selected) {
+                    idx = i;
+                    break;
+                }
+                else if (!default_ops[i].is_locked) idx += 1;
+            }
+            texed_add_op(idx);
         }
     }
 }