diff --git a/alfred/npm.py b/alfred/npm.py
index 7a4f52584..e6946dfcb 100644
--- a/alfred/npm.py
+++ b/alfred/npm.py
@@ -5,7 +5,8 @@
 
 @alfred.command("npm.lint", help="lint check npm packages")
 def npm_lint():
-    alfred.run("npm run ui:lint:ci")
+    alfred.run("npm run ui:lint.ci")
+    alfred.run("npm run ui:custom.check")
 
 @alfred.command("npm.e2e", help="run e2e tests")
 @alfred.option('--browser', '-b', help="run e2e tests on specified browser", default='chromium')
diff --git a/docs/framework/custom-components.mdx b/docs/framework/custom-components.mdx
index a37c26417..5ce899008 100644
--- a/docs/framework/custom-components.mdx
+++ b/docs/framework/custom-components.mdx
@@ -165,13 +165,18 @@ A single or multiple templates can be specified. Take into account that they wil
 
 ## Bundling templates
 
-Execute `npm run custom.build`, this will generate the output `.js` and `.css` files into `ui/custom_components_dist`.
+Execute `npm run custom.build` into `src/ui`, this will generate the output `.js` and `.css` files into `./custom_components_dist`.
 
 ```sh
 # "build" builds the entire front-end
 # "custom.build" only builds the custom templates
 
+npm run custom.check # Optional: checks certain issues on custom components
 npm run custom.build
 ```
 
-Collect the files from `ui/custom_components_dist` and pack them in a folder such as `my_custom_bubbles`. The folder containing the generated files, e.g. `my_custom_bubbles`, can now be placed in the `extensions/` folder of any Framework project. It'll be automatically detected during server startup.
+Collect the files from `./custom_components_dist` and pack them in a folder such as `my_custom_bubbles`. The folder containing the generated files, e.g. `my_custom_bubbles`, can now be placed in the `extensions/` folder of any Framework project. It'll be automatically detected during server startup.
+
+<Tip>
+The `custom.check` command is optional, but it's recommended to run it before building the custom components. It checks for common issues in the custom components, such as invalid key declaration, ...
+</Tip>
diff --git a/package.json b/package.json
index 2d749778c..2215771c0 100644
--- a/package.json
+++ b/package.json
@@ -29,8 +29,9 @@
 		"ui:build": "npm run -w writer-ui build",
 		"ui:preview": "npm run -w writer-ui preview",
 		"ui:custom.build": "npm run -w writer-ui custom.build",
+		"ui:custom.check": "npm run -w writer-ui custom.check",
 		"ui:lint": "npm run -w writer-ui lint",
-		"ui:lint:ci": "npm run -w writer-ui lint:ci",
+		"ui:lint.ci": "npm run -w writer-ui lint.ci",
 
 		"docs:codegen": "npm run -w writer-docs codegen",
 		"docs:preview": "npm run -w writer-docs preview",
diff --git a/src/ui/package.json b/src/ui/package.json
index 590dcfd78..aabcd24cd 100644
--- a/src/ui/package.json
+++ b/src/ui/package.json
@@ -7,10 +7,11 @@
 		"build": "vite build",
 		"preview": "vite preview --port 5050",
 		"lint": "eslint . --ext .vue,.js,.jsx,.cjs,.mjs --fix --ignore-path ../../.gitignore --ignore-path .gitignore",
-		"lint:ci": "eslint . --ext .vue,.js,.jsx,.cjs,.mjs --ignore-path ../../.gitignore --ignore-path .gitignore",
+		"lint.ci": "eslint . --ext .vue,.js,.jsx,.cjs,.mjs --ignore-path ../../.gitignore --ignore-path .gitignore",
 		"codegen": "node tools/generator.mjs",
 		"custom.dev": "vite --config vite.config.custom.ts",
 		"custom.build": "vite build --config vite.config.custom.ts",
+		"custom.check": "node tools/custom_check.mjs",
 		"storybook": "storybook dev -p 6006",
 		"storybook.build": "storybook build"
 	},
@@ -61,4 +62,4 @@
 		"eslint-plugin-storybook": "0.8.0",
 		"storybook": "8.0.5"
 	}
-}
\ No newline at end of file
+}
diff --git a/src/ui/src/core/loadExtensions.ts b/src/ui/src/core/loadExtensions.ts
index 74f312dbe..80a72fedb 100644
--- a/src/ui/src/core/loadExtensions.ts
+++ b/src/ui/src/core/loadExtensions.ts
@@ -20,12 +20,33 @@ async function importCustomComponentTemplate(path: string) {
 	await import(/* @vite-ignore */ getRelativeExtensionsPath() + path);
 	Object.entries(window[CUSTOM_COMPONENTS_GLOBAL_VAR])?.forEach(
 		([key, template]) => {
-			console.log(`Registering template for "${key}".`);
-			registerComponentTemplate(`custom_${key}`, template);
+			if (checkComponentKey(key)) {
+				registerComponentTemplate(`custom_${key}`, template);
+				console.log(`Registering template for "${key}".`);
+			} else {
+				console.warn(
+					`custom component '${key}' is ignored. A custom component should be declared using only alphanumeric lowercase and _.`,
+				);
+			}
 		},
 	);
 }
 
+/**
+ * 	Checks that the key contains only alphanumeric characters and underscores without capital letters
+ * 	The clipboard api use in drag and drop doesn't handle uppercase.
+ *
+ * 	mycomponent : valid
+ * 	myComponent : invalid
+ * 	myCOMPONENT : invalid
+ *
+ * 	@see https://github.com/writer/writer-framework/issues/517
+ */
+export function checkComponentKey(key: string): boolean {
+	const isValidKey = /^[a-z0-9_]+$/.test(key);
+	return isValidKey;
+}
+
 function loadStylesheet(path: string) {
 	const el: HTMLLinkElement = document.createElement("link");
 	el.rel = "stylesheet";
@@ -41,3 +62,5 @@ function getRelativeExtensionsPath() {
 
 	return `${pathname}extensions/`;
 }
+
+
diff --git a/src/ui/tools/core.mjs b/src/ui/tools/core.mjs
index 742d71c28..8219eea0b 100644
--- a/src/ui/tools/core.mjs
+++ b/src/ui/tools/core.mjs
@@ -28,3 +28,21 @@ export async function loadComponents() {
 
 	return data;
 }
+
+/**
+ * imports a vue-dependent module.
+ */
+export async function importVue(modulePath) {
+	const vite = await createServer({
+		includeWriterComponentPath: true,
+		server: {
+			middlewareMode: true,
+		},
+		appType: "custom",
+	});
+
+	const m = await vite.ssrLoadModule(path.join(__dirname, modulePath));
+	await vite.close();
+
+	return m;
+}
diff --git a/src/ui/tools/custom_check.mjs b/src/ui/tools/custom_check.mjs
new file mode 100644
index 000000000..49b26aa70
--- /dev/null
+++ b/src/ui/tools/custom_check.mjs
@@ -0,0 +1,42 @@
+import { importVue } from "./core.mjs";
+
+async function checkDeclarationKey() {
+	let hasFailed = false;
+	const module = await importVue("../src/custom_components/index.ts");
+	const { checkComponentKey } = await importVue(
+		"../src/core/loadExtensions.ts",
+	);
+	const invalidCustomComponentKeys = [];
+	Object.keys(module.default).forEach((key) => {
+		if (!checkComponentKey(key)) {
+			invalidCustomComponentKeys.push(key);
+			hasFailed = true;
+		}
+	});
+
+	if (invalidCustomComponentKeys.length !== 0) {
+		// eslint-disable-next-line no-console
+		console.error(
+			`ERROR: Invalid component declaration: ${invalidCustomComponentKeys} into 'src/custom_components/index.ts'. Their key must be declared using only lowercase and alphanumeric characters.`,
+		);
+	}
+	return hasFailed;
+}
+
+/**
+ * Check the custom components in continuous integration
+ *
+ * npm run custom.check
+ *
+ */
+async function check() {
+	let hasFailed = false;
+
+	hasFailed |= await checkDeclarationKey();
+
+	if (hasFailed) {
+		process.exit(1);
+	}
+}
+
+check();