diff --git a/apisix/plugin.lua b/apisix/plugin.lua
index 18954f47e1d4..fc24778127a8 100644
--- a/apisix/plugin.lua
+++ b/apisix/plugin.lua
@@ -102,12 +102,27 @@ local function load_plugin(name, plugins_list, is_stream_plugin)
         return
     end
 
-    if plugin.schema and plugin.schema.type == "object" then
-        if not plugin.schema.properties or
-           core.table.nkeys(plugin.schema.properties) == 0
-        then
-            plugin.schema.properties = core.schema.plugin_disable_schema
+    if type(plugin.schema) ~= "table" then
+        core.log.error("invalid plugin [", name, "] schema field")
+        return
+    end
+
+    if not plugin.schema.properties then
+        plugin.schema.properties = {}
+    end
+
+    local properties = plugin.schema.properties
+    local plugin_injected_schema = core.schema.plugin_injected_schema
+
+    if properties['$comment'] ~= plugin_injected_schema['$comment'] then
+        if properties.disable then
+            core.log.error("invalid plugin [", name,
+                           "]: found forbidden 'disable' field in the schema")
+            return
         end
+
+        properties.disable = plugin_injected_schema.disable
+        properties['$comment'] = plugin_injected_schema['$comment']
     end
 
     plugin.name = name
diff --git a/apisix/schema_def.lua b/apisix/schema_def.lua
index daa4acea4fa8..7d9cf49a97c9 100644
--- a/apisix/schema_def.lua
+++ b/apisix/schema_def.lua
@@ -739,8 +739,11 @@ _M.plugins = {
 _M.id_schema = id_schema
 
 
-_M.plugin_disable_schema = {
-    disable = {type = "boolean"}
+_M.plugin_injected_schema = {
+    ["$comment"] = "this is a mark for our injected plugin schema",
+    disable = {
+        type = "boolean",
+    }
 }
 
 
diff --git a/t/control/schema.t b/t/control/schema.t
index c1197cfc1d2d..ac0c124e70f3 100644
--- a/t/control/schema.t
+++ b/t/control/schema.t
@@ -60,16 +60,26 @@ __DATA__
                         "upstream": {"type":"object"},
                         "upstream_hash_header_schema": {"type":"string"},
                         "upstream_hash_vars_schema": {"type":"string"},
-                    },
+                    },]] .. [[
                     "plugins": {
                         "example-plugin": {
                             "version": 0.1,
                             "priority": 0,
-                            "schema": {"type":"object"},
+                            "schema": {
+                                "type":"object",
+                                "properties": {
+                                    "disable": {"type": "boolean"}
+                                }
+                            },
                             "metadata_schema": {"type":"object"}
                         },
                         "mqtt-proxy": {
-                            "schema": {"type":"object"},
+                            "schema": {
+                                "type":"object",
+                                "properties": {
+                                    "disable": {"type": "boolean"}
+                                }
+                            },
                             "priority": 1000
                         },
                         "basic-auth": {