diff --git a/.changeset/strong-catalogs-load.md b/.changeset/strong-catalogs-load.md
new file mode 100644
index 0000000000..2cd5cf2de2
--- /dev/null
+++ b/.changeset/strong-catalogs-load.md
@@ -0,0 +1,5 @@
+---
+"@cloudflare/kumo": patch
+---
+
+Load catalog schemas when `initCatalog` is awaited so synchronous validation is ready to use.
diff --git a/packages/kumo/AGENTS.md b/packages/kumo/AGENTS.md
index 891062a551..023c792898 100644
--- a/packages/kumo/AGENTS.md
+++ b/packages/kumo/AGENTS.md
@@ -120,7 +120,6 @@ Output: ai/component-registry.{json,md} + ai/schemas.ts
 - **Compound components**: CommandPalette (14 sub-components), Dialog, Select use two-level contexts
 - **13 components use createContext**: SwitchGroup, PaginationContext, RadioGroup, FlowNodeAnchor, Diagram, Descendants, InputGroup, DialogRole, ComboboxSize, Grid, CheckboxGroup, CommandPalette (2)
 - **DateRangePicker**: Contains 150 lines of duplicated ternary logic (refactoring target)
-- **Catalog `initCatalog`**: Appears to have race condition with async schema loading
 - **CLI path inconsistency**: `ls`/`doc` read from `catalog/`, `blocks` from `ai/` directory
 - **`PLOP_INJECT_EXPORT`** in `src/index.ts` and `PLOP_INJECT_COMPONENT_ENTRY` in `vite.config.ts` are scaffolding markers
 - **5th lint rule** (`no-deprecated-props`): Only in `packages/kumo/lint/`, reads deprecation data from registry
diff --git a/packages/kumo/src/catalog/catalog.test.ts b/packages/kumo/src/catalog/catalog.test.ts
index d1ada7df7b..2d4ebbceaa 100644
--- a/packages/kumo/src/catalog/catalog.test.ts
+++ b/packages/kumo/src/catalog/catalog.test.ts
@@ -3,6 +3,7 @@
  */
 
 import { describe, it, expect } from "vitest";
+import { createKumoCatalog, initCatalog } from "./catalog";
 import {
   getByPath,
   setByPath,
@@ -12,6 +13,30 @@ import {
 } from "./data";
 import { evaluateVisibility, createVisibilityContext } from "./visibility";
 
+describe("catalog initialization", () => {
+  it("loads schemas before synchronous validation", async () => {
+    const catalog = createKumoCatalog();
+
+    await initCatalog(catalog);
+
+    expect(catalog.componentNames).toContain("Button");
+    expect(catalog.hasComponent("Button")).toBe(true);
+    expect(catalog.validateTree({})).toEqual({
+      success: false,
+      error: [
+        {
+          message: "Invalid input: expected string, received undefined",
+          path: ["root"],
+        },
+        {
+          message: "Invalid input: expected record, received undefined",
+          path: ["elements"],
+        },
+      ],
+    });
+  });
+});
+
 describe("data utilities", () => {
   describe("getByPath", () => {
     it("returns root for empty path", () => {
diff --git a/packages/kumo/src/catalog/catalog.ts b/packages/kumo/src/catalog/catalog.ts
index e024aba833..94e7b11699 100644
--- a/packages/kumo/src/catalog/catalog.ts
+++ b/packages/kumo/src/catalog/catalog.ts
@@ -276,7 +276,6 @@ export function createKumoCatalog(config: CatalogConfig = {}): KumoCatalog {
  * Initialize the catalog by loading schemas.
  * Call this before using synchronous validation methods.
  */
-export async function initCatalog(catalog: KumoCatalog): Promise<void> {
-  // Trigger a validation to load schemas
-  catalog.validateTree({});
+export async function initCatalog(_catalog: KumoCatalog): Promise<void> {
+  await loadSchemas();
 }