diff --git a/src/compiler/code_generator.ts b/src/compiler/code_generator.ts
index 673e3cdf..d983c933 100644
--- a/src/compiler/code_generator.ts
+++ b/src/compiler/code_generator.ts
@@ -39,6 +39,7 @@ export interface CodeGenOptions extends Config {
 // of HTML (as we will parse it as xml later)
 const xmlDoc = document.implementation.createDocument(null, null, null);
 
+const MODS = new Set(["stop", "capture", "prevent", "self", "synthetic"]);
 // -----------------------------------------------------------------------------
 // BlockDescription
 // -----------------------------------------------------------------------------
@@ -504,7 +505,12 @@ export class CodeGenerator {
     const modifiers = rawEvent
       .split(".")
       .slice(1)
-      .map((m) => `"${m}"`);
+      .map((m) => {
+        if (!MODS.has(m)) {
+          throw new Error(`Unknown event modifier: '${m}'`);
+        }
+        return `"${m}"`;
+      });
     let modifiersCode = "";
     if (modifiers.length) {
       modifiersCode = `${modifiers.join(",")}, `;
@@ -1022,6 +1028,8 @@ export class CodeGenerator {
           this.helpers.add("bind");
           propName = name;
           propValue = `bind(ctx, ${propValue})`;
+        } else {
+          throw new Error("Invalid prop suffix");
         }
       }
       propName = /^[a-z_]+$/i.test(propName) ? propName : `'${propName}'`;
diff --git a/tests/compiler/event_handling.test.ts b/tests/compiler/event_handling.test.ts
index 90603830..e363b62d 100644
--- a/tests/compiler/event_handling.test.ts
+++ b/tests/compiler/event_handling.test.ts
@@ -480,6 +480,14 @@ describe("t-on", () => {
       button.click();
     });
 
+    test("t-on crashes when used with unknown modifier", async () => {
+      const template = `<div t-on-click.somemodifier="onClick" />`;
+
+      let owner = { onClick(e: Event) {} };
+
+      expect(() => mountToFixture(template, owner)).toThrowError("Unknown event modifier");
+    });
+
     test("t-on combined with t-esc", async () => {
       expect.assertions(3);
       const template = `<div><button t-on-click="onClick" t-esc="text"/></div>`;
diff --git a/tests/components/__snapshots__/props.test.ts.snap b/tests/components/__snapshots__/props.test.ts.snap
index 57fe3991..bf5feaef 100644
--- a/tests/components/__snapshots__/props.test.ts.snap
+++ b/tests/components/__snapshots__/props.test.ts.snap
@@ -122,7 +122,7 @@ exports[`basics support prop names that aren't valid bare object property names
   let { text, createBlock, list, multi, html, toggler, component, comment } = bdom;
   
   return function template(ctx, node, key = \\"\\") {
-    return component(\`Child\`, {'some-dashed-prop': 5,'a.b': 'keyword prop'}, key + \`__1\`, node, ctx);
+    return component(\`Child\`, {'some-dashed-prop': 5}, key + \`__1\`, node, ctx);
   }
 }"
 `;
diff --git a/tests/components/props.test.ts b/tests/components/props.test.ts
index 902341a4..88da8a3a 100644
--- a/tests/components/props.test.ts
+++ b/tests/components/props.test.ts
@@ -142,17 +142,16 @@ describe("basics", () => {
   });
 
   test("support prop names that aren't valid bare object property names", async () => {
-    expect.assertions(4);
+    expect.assertions(3);
     class Child extends Component {
       static template = xml`<button t-on-click="props.onClick"/>`;
       setup() {
         expect(this.props["some-dashed-prop"]).toBe(5);
-        expect(this.props["a.b"]).toBe("keyword prop");
       }
     }
 
     class Parent extends Component {
-      static template = xml`<Child some-dashed-prop="5" a.b="'keyword prop'"/>`;
+      static template = xml`<Child some-dashed-prop="5"/>`;
       static components = { Child };
     }
     await mount(Parent, fixture);
@@ -225,3 +224,18 @@ test("bound functions is referentially equal after update", async () => {
   expect(fixture.innerHTML).toBe("3");
   expect(isEqual).toBe(true);
 });
+
+test("throw if prop uses an unknown suffix", async () => {
+  class Child extends Component {
+    static template = xml`<t t-esc="props.val"/>`;
+  }
+
+  class Parent extends Component {
+    static template = xml`<Child val.somesuffix="state.val"/>`;
+    static components = { Child };
+  }
+
+  await expect(async () => {
+    await mount(Parent, fixture);
+  }).rejects.toThrowError("Invalid prop suffix");
+});