diff --git a/tests/setup.ts b/tests/setup.ts
new file mode 100644
index 0000000..b56b9f4
--- /dev/null
+++ b/tests/setup.ts
@@ -0,0 +1,10 @@
+import { vi } from "vitest";
+
+// Mock sharp globally — it's a native binary module that may not be available in CI
+vi.mock("sharp", () => ({
+  default: vi.fn().mockReturnValue({
+    png: vi.fn().mockReturnValue({
+      toBuffer: vi.fn().mockResolvedValue(Buffer.from("mock-image")),
+    }),
+  }),
+}));
diff --git a/vite.config.ts b/vite.config.ts
index 9828231..ed038a7 100644
--- a/vite.config.ts
+++ b/vite.config.ts
@@ -4,7 +4,6 @@ import { defineConfig } from 'vite'
 
 export default defineConfig({
   test: {
-    /* for example, use global to avoid globals imports (describe, test, expect): */
-    // globals: true,
+    setupFiles: ['./tests/setup.ts'],
   },
 })
\ No newline at end of file