diff --git a/codegen/codegen.go b/codegen/codegen.go
index b8a1c80..599cc27 100644
--- a/codegen/codegen.go
+++ b/codegen/codegen.go
@@ -140,6 +140,13 @@ func GenerateTypeDefinitions(slots map[string]string) (string, error) {
 	}
 
 	b.WriteString("\ndeclare global {\n")
+	b.WriteString("  interface WcReadyDetail {\n")
+	b.WriteString("    tag: string;\n")
+	b.WriteString("    slot: string;\n")
+	b.WriteString("  }\n")
+	b.WriteString("  interface HTMLElementEventMap {\n")
+	b.WriteString(`    "wc-ready": CustomEvent<WcReadyDetail>;` + "\n")
+	b.WriteString("  }\n")
 	b.WriteString("  interface HTMLElementTagNameMap {\n")
 	for _, entry := range entries {
 		if !isValidCustomElementTag(entry.Tag) {
diff --git a/codegen/codegen_test.go b/codegen/codegen_test.go
index ccfe3b3..330b116 100644
--- a/codegen/codegen_test.go
+++ b/codegen/codegen_test.go
@@ -76,6 +76,9 @@ func TestGenerateTypeDefinitions_Good(t *testing.T) {
 	dts, err := GenerateTypeDefinitions(slots)
 	require.NoError(t, err)
 	assert.Contains(t, dts, "declare global")
+	assert.Contains(t, dts, "interface WcReadyDetail")
+	assert.Contains(t, dts, `interface HTMLElementEventMap`)
+	assert.Contains(t, dts, `"wc-ready": CustomEvent<WcReadyDetail>;`)
 	assert.Contains(t, dts, "class NavBar extends HTMLElement")
 	assert.Contains(t, dts, "class MainContent extends HTMLElement")
 	assert.Contains(t, dts, `"nav-bar": NavBar;`)