diff --git a/packages/generator-widget/CHANGELOG.md b/packages/generator-widget/CHANGELOG.md
index 9d4f7bb4..203ec15a 100644
--- a/packages/generator-widget/CHANGELOG.md
+++ b/packages/generator-widget/CHANGELOG.md
@@ -12,6 +12,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 -   We changed the copyright prompt to prefill the current year.
 
+-   We now enforce validation when choosing an organization name for a widget.
+
 ## [10.24.0] - 2025-09-24
 
 ### Changed
diff --git a/packages/generator-widget/generators/app/lib/prompttexts.js b/packages/generator-widget/generators/app/lib/prompttexts.js
index 4decd73c..b1ce7ad1 100644
--- a/packages/generator-widget/generators/app/lib/prompttexts.js
+++ b/packages/generator-widget/generators/app/lib/prompttexts.js
@@ -9,7 +9,7 @@ function promptWidgetProperties(mxProjectDir, widgetName) {
                 if (/^([a-zA-Z]+)$/.test(input)) {
                     return true;
                 }
-                return "Your widget name can only contain one or more letters (a-z & A-Z). Please provide a valid name";
+                return "Your widget name may only contain characters matching [a-zA-Z]. Please provide a valid name.";
             },
             message: "What is the name of your widget?",
             default: widgetName ? widgetName : "MyWidget"
@@ -23,6 +23,15 @@ function promptWidgetProperties(mxProjectDir, widgetName) {
         {
             type: "input",
             name: "organization",
+            validate: input => {
+                if (/[^a-zA-Z0-9_.-]/.test(input)) {
+                    return "Your organization name may only contain characters matching [a-zA-Z0-9_.-]. Please provide a valid name.";
+                }
+                if (!/^([a-zA-Z0-9_-]+.)*[a-zA-Z0-9_-]+$/.test(input)) {
+                    return "Your organization name must follow the structure (namespace.)org-name, for example 'mendix' or 'com.mendix.widgets'. Please provide a valid name.";
+                }
+                return true;
+            },
             message: "Organization name",
             default: "Mendix",
             store: true
diff --git a/packages/pluggable-widgets-tools/CHANGELOG.md b/packages/pluggable-widgets-tools/CHANGELOG.md
index fb9ae935..06f35784 100644
--- a/packages/pluggable-widgets-tools/CHANGELOG.md
+++ b/packages/pluggable-widgets-tools/CHANGELOG.md
@@ -14,6 +14,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 - We fixed an issue where `require` was not transformed to `import` for the `es` output format which could result in an error when the widget was used in a project with React client enabled.  
 
+-   We now enforce the same validation for the `widgetName` in the widget bundler as we do in the generator. Validation is now also enforced for the organization name (`packagePath`).
+
 ## [11.3.0] - 2025-11-12
 
 ### Changed
diff --git a/packages/pluggable-widgets-tools/configs/shared.mjs b/packages/pluggable-widgets-tools/configs/shared.mjs
index 80098b07..e58f8be1 100644
--- a/packages/pluggable-widgets-tools/configs/shared.mjs
+++ b/packages/pluggable-widgets-tools/configs/shared.mjs
@@ -4,6 +4,7 @@ import { existsSync, readdirSync, promises as fs, readFileSync } from "node:fs";
 import { join, relative } from "node:path";
 import { config } from "dotenv";
 import colors from "ansi-colors";
+import { throwOnIllegalChars, throwOnNoMatch } from "../dist/utils/validation.js";
 
 config({ path: join(process.cwd(), ".env") });
 
@@ -25,6 +26,10 @@ if (!widgetName || !widgetPackageJson) {
     throw new Error("Widget does not define widgetName in its package.json");
 }
 
+throwOnIllegalChars(widgetName, "a-zA-Z", "The `widgetName` property in package.json")
+throwOnIllegalChars(widgetPackage, "a-zA-Z0-9_.-", "The `packagePath` property in package.json")
+throwOnNoMatch(widgetPackage, /^([a-zA-Z0-9_-]+.)*[a-zA-Z0-9_-]+$/, "The `packagePath` property in package.json")
+
 const widgetSrcFiles = readdirSync(join(sourcePath, "src")).map(file => join(sourcePath, "src", file));
 export const widgetEntry = widgetSrcFiles.filter(file =>
     file.match(new RegExp(`[/\\\\]${escape(widgetName)}\\.[jt]sx?$`, "i"))
diff --git a/packages/pluggable-widgets-tools/src/utils/__tests__/validation.spec.ts b/packages/pluggable-widgets-tools/src/utils/__tests__/validation.spec.ts
new file mode 100644
index 00000000..60a68cbc
--- /dev/null
+++ b/packages/pluggable-widgets-tools/src/utils/__tests__/validation.spec.ts
@@ -0,0 +1,28 @@
+import { WidgetValidationError, throwOnIllegalChars, throwOnNoMatch } from "../validation"
+
+describe("Validation Utilities", () => {
+
+    describe("throwOnIllegalChars", () => {
+
+        it("throws when the input does not match the pattern", () => {
+            expect(throwOnIllegalChars.bind(null, "abc", '0-9', "Test")).toThrow(WidgetValidationError)
+        })
+
+        it("does not throw when the input does match the pattern", () => {
+            expect(throwOnIllegalChars.bind(null, "abc", 'a-z', "Test")).not.toThrow()
+        })
+    })
+
+    describe("throwOnNoMatch", () => {
+
+        it("throws when the input does not match the pattern", () => {
+            expect(throwOnNoMatch.bind(null, "abc", /^$/, "Test")).toThrow(WidgetValidationError)
+        })
+
+        it("does not throw when the input does match the pattern", () => {
+            expect(throwOnNoMatch.bind(null, "abc", /[a-z]/, "Test")).not.toThrow()
+        })
+    })
+
+})
+
diff --git a/packages/pluggable-widgets-tools/src/utils/validation.ts b/packages/pluggable-widgets-tools/src/utils/validation.ts
new file mode 100644
index 00000000..efe5d65d
--- /dev/null
+++ b/packages/pluggable-widgets-tools/src/utils/validation.ts
@@ -0,0 +1,47 @@
+
+export class WidgetValidationError extends Error {
+    name = "Widget Validation Error"
+
+    constructor(message: string) {
+        super(message)
+    }
+}
+
+/**
+ * Asserts that the given input string only contains the characters specified by `legalCharacters`.
+ * @param input The string under test
+ * @param legalCharacters The characters that the input string may contain. Follows character class notation from regex (inside the [])
+ * @param message The message that is included in the error. Specify where the input is used and can be corrected.
+ * @throws WidgetValidationError If the input contains characters not allowed by legalCharacters
+ */
+export function throwOnIllegalChars(input: string, legalCharacters: string, message: string): void {
+    const pattern = new RegExp(`([^${legalCharacters}])`, "g")
+    const illegalChars = input.match(pattern);
+
+    if (illegalChars === null) {
+        return
+    }
+
+    const formatted = illegalChars
+        .reduce((unique, c) => unique.includes(c) ? unique : [...unique, c], [] as string[])
+        .map(c => `"${c}"`)
+        .join(", ");
+
+    throw new WidgetValidationError(`${message} contains illegal characters ${formatted}. Allowed characters are [${legalCharacters}].`)
+}
+
+/**
+ * Asserts that the given input string matches the given pattern.
+ * @param input The string under test
+ * @param pattern The pattern the input must match
+ * @param message The message that is included in the error. Specify where the input is used and can be corrected.
+ * @throws WidgetValidationError If the input contains characters not allowed by legalCharacters
+ */
+export function throwOnNoMatch(input: string, pattern: RegExp, message: string) {
+    if (pattern.test(input)) {
+        return
+    }
+
+    throw new WidgetValidationError(`${message} does not match the pattern ${pattern}.`)
+}
+