diff --git a/src/component/props_validation.ts b/src/component/props_validation.ts
index 5aebdd62..bae01d94 100644
--- a/src/component/props_validation.ts
+++ b/src/component/props_validation.ts
@@ -19,6 +19,14 @@ export function applyDefaultProps(props: { [key: string]: any }, ComponentClass:
 //------------------------------------------------------------------------------
 // Prop validation helper
 //------------------------------------------------------------------------------
+function getPropDescription(staticProps: any) {
+  if (staticProps instanceof Array) {
+    return Object.fromEntries(
+      staticProps.map((p) => (p.endsWith("?") ? [p.slice(0, -1), false] : [p, true]))
+    );
+  }
+  return staticProps || { "*": true };
+}
 
 /**
  * Validate the component props (or next props) against the (static) props
@@ -33,46 +41,34 @@ export const validateProps = function (name: string | typeof Component, props: a
 
   applyDefaultProps(props, ComponentClass);
 
-  const propsDef = ComponentClass.props;
-  if (propsDef instanceof Array) {
-    // list of strings (prop names)
-    for (const propName of propsDef) {
-      if (propName[propName.length - 1] === "?") {
-        // optional prop
-        break;
-      }
-      if (!(propName in props)) {
+  let propsDef = getPropDescription(ComponentClass.props);
+  const allowAdditionalProps = "*" in propsDef;
+
+  for (let propName in propsDef) {
+    if (propName === "*") {
+      continue;
+    }
+    if (props[propName] === undefined) {
+      if (propsDef[propName] && !propsDef[propName].optional) {
         throw new Error(`Missing props '${propName}' (component '${ComponentClass.name}')`);
+      } else {
+        continue;
       }
     }
-    for (let key in props) {
-      if (!propsDef.includes(key) && !propsDef.includes(key + "?")) {
-        throw new Error(`Unknown prop '${key}' given to component '${ComponentClass.name}'`);
-      }
+    let isValid;
+    try {
+      isValid = isValidProp(props[propName], propsDef[propName]);
+    } catch (e) {
+      (e as Error).message = `Invalid prop '${propName}' in component ${ComponentClass.name} (${
+        (e as Error).message
+      })`;
+      throw e;
     }
-  } else if (propsDef) {
-    // propsDef is an object now
-    for (let propName in propsDef) {
-      if (props[propName] === undefined) {
-        if (propsDef[propName] && !propsDef[propName].optional) {
-          throw new Error(`Missing props '${propName}' (component '${ComponentClass.name}')`);
-        } else {
-          continue;
-        }
-      }
-      let isValid;
-      try {
-        isValid = isValidProp(props[propName], propsDef[propName]);
-      } catch (e) {
-        (e as Error).message = `Invalid prop '${propName}' in component ${ComponentClass.name} (${
-          (e as Error).message
-        })`;
-        throw e;
-      }
-      if (!isValid) {
-        throw new Error(`Invalid Prop '${propName}' in component '${ComponentClass.name}'`);
-      }
+    if (!isValid) {
+      throw new Error(`Invalid Prop '${propName}' in component '${ComponentClass.name}'`);
     }
+  }
+  if (!allowAdditionalProps) {
     for (let propName in props) {
       if (!(propName in propsDef)) {
         throw new Error(`Unknown prop '${propName}' given to component '${ComponentClass.name}'`);
diff --git a/tests/components/__snapshots__/props_validation.test.ts.snap b/tests/components/__snapshots__/props_validation.test.ts.snap
index 82dfe1ec..75ef0ec8 100644
--- a/tests/components/__snapshots__/props_validation.test.ts.snap
+++ b/tests/components/__snapshots__/props_validation.test.ts.snap
@@ -96,6 +96,58 @@ exports[`default props default values are also set whenever component is updated
 }"
 `;
 
+exports[`props validation can specify that additional props are allowed (array) 1`] = `
+"function anonymous(bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, component, comment } = bdom;
+  
+  return function template(ctx, node, key = \\"\\") {
+    const props1 = {message: 'm',otherProp: 'o'}
+    helpers.validateProps(\`Child\`, props1, ctx)
+    return component(\`Child\`, props1, key + \`__2\`, node, ctx);
+  }
+}"
+`;
+
+exports[`props validation can specify that additional props are allowed (array) 2`] = `
+"function anonymous(bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, component, comment } = bdom;
+  
+  let block1 = createBlock(\`<div>hey</div>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    return block1();
+  }
+}"
+`;
+
+exports[`props validation can specify that additional props are allowed (object) 1`] = `
+"function anonymous(bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, component, comment } = bdom;
+  
+  return function template(ctx, node, key = \\"\\") {
+    const props1 = {message: 'm',otherProp: 'o'}
+    helpers.validateProps(\`Child\`, props1, ctx)
+    return component(\`Child\`, props1, key + \`__2\`, node, ctx);
+  }
+}"
+`;
+
+exports[`props validation can specify that additional props are allowed (object) 2`] = `
+"function anonymous(bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, component, comment } = bdom;
+  
+  let block1 = createBlock(\`<div>hey</div>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    return block1();
+  }
+}"
+`;
+
 exports[`props validation can validate a prop with multiple types 1`] = `
 "function anonymous(bdom, helpers
 ) {
diff --git a/tests/components/props_validation.test.ts b/tests/components/props_validation.test.ts
index b21a7ac8..40300138 100644
--- a/tests/components/props_validation.test.ts
+++ b/tests/components/props_validation.test.ts
@@ -723,6 +723,36 @@ describe("props validation", () => {
     expect(error!).toBeDefined();
     expect(error!.message).toBe("Missing props 'mandatory' (component 'Child')");
   });
+
+  test("can specify that additional props are allowed (array)", async () => {
+    class Child extends Component {
+      static props = ["message", "*"];
+      static template = xml`<div>hey</div>`;
+    }
+    class Parent extends Component {
+      static template = xml`<Child message="'m'" otherProp="'o'"/>`;
+      static components = { Child };
+    }
+
+    await expect(mount(Parent, fixture, { dev: true })).resolves.toEqual(expect.anything());
+  });
+
+  test("can specify that additional props are allowed (object)", async () => {
+    class Child extends Component {
+      static props = {
+        message: { type: String },
+        "*": true,
+      };
+      static template = xml`<div>hey</div>`;
+    }
+    class Parent extends Component {
+      static template = xml`<Child message="'m'" otherProp="'o'"/>`;
+      static components = { Child };
+    }
+
+    // we just check that it doesn't throw
+    await expect(mount(Parent, fixture, { dev: true })).resolves.toEqual(expect.anything());
+  });
 });
 
 //------------------------------------------------------------------------------
diff --git a/tsconfig.json b/tsconfig.json
index a7a29b1f..be2ede4a 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -13,7 +13,7 @@
   // "compileOnSave": false,                                    // Signals to the IDE to generate all files for a given tsconfig.json upon saving.
   "compilerOptions": {
                                                                 // Main options
-    "target": "es2017",                                         // Specify ECMAScript target version: 'es3' (default), 'es5', 'es2015', 'es2016', 'es2017','es2018' or 'esnext'.
+    "target": "es2019",                                         // Specify ECMAScript target version: 'es3' (default), 'es5', 'es2015', 'es2016', 'es2017','es2018' or 'esnext'.
     "module": "es6",                                         // Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'.
     // "lib": ["esnext", "dom"],                                // Specify library files to be included in the compilation.
     // "allowJs": false,                                        // Allow javascript files to be compiled.