diff --git a/extensions/configuration-editing/schemas/attachContainer.schema.json b/extensions/configuration-editing/schemas/attachContainer.schema.json
index 58e59d72ee0..9ede055f4c1 100644
--- a/extensions/configuration-editing/schemas/attachContainer.schema.json
+++ b/extensions/configuration-editing/schemas/attachContainer.schema.json
@@ -3,9 +3,11 @@
 	"description": "Configures an attached to container",
 	"allowComments": true,
 	"type": "object",
+	"additionalProperties": false,
 	"definitions": {
 		"attachContainer": {
 			"type": "object",
+			"additionalProperties": false,
 			"properties": {
 				"workspaceFolder": {
 					"type": "string",
diff --git a/extensions/configuration-editing/schemas/devContainer.schema.json b/extensions/configuration-editing/schemas/devContainer.schema.json
index 292fe629937..dde1a7cf256 100644
--- a/extensions/configuration-editing/schemas/devContainer.schema.json
+++ b/extensions/configuration-editing/schemas/devContainer.schema.json
@@ -3,9 +3,11 @@
 	"description": "Defines a dev container",
 	"allowComments": true,
 	"type": "object",
+	"additionalProperties": false,
 	"definitions": {
 		"devContainerCommon": {
 			"type": "object",
+			"additionalProperties": false,
 			"properties": {
 				"name": {
 					"type": "string",
@@ -63,6 +65,7 @@
 		},
 		"nonComposeBase": {
 			"type": "object",
+			"additionalProperties": false,
 			"properties": {
 				"appPort": {
 					"type": [
@@ -131,6 +134,7 @@
 		},
 		"dockerFileContainer": {
 			"type": "object",
+			"additionalProperties": false,
 			"properties": {
 				"dockerFile": {
 					"type": "string",
@@ -147,6 +151,7 @@
 		},
 		"imageContainer": {
 			"type": "object",
+			"additionalProperties": false,
 			"properties": {
 				"image": {
 					"type": "string",
@@ -159,6 +164,7 @@
 		},
 		"composeContainer": {
 			"type": "object",
+			"additionalProperties": false,
 			"properties": {
 				"dockerComposeFile": {
 					"type": [