diff --git a/.changeset/purple-steaks-admire.md b/.changeset/purple-steaks-admire.md
new file mode 100644
index 0000000000..1765aa59f9
--- /dev/null
+++ b/.changeset/purple-steaks-admire.md
@@ -0,0 +1,6 @@
+---
+"@marko/babel-utils": patch
+"@marko/compiler": patch
+---
+
+Improve some typings for the compiler apis.
diff --git a/packages/babel-utils/index.d.ts b/packages/babel-utils/index.d.ts
index c6ab82d8e2..2785216974 100644
--- a/packages/babel-utils/index.d.ts
+++ b/packages/babel-utils/index.d.ts
@@ -19,10 +19,10 @@ export interface AttributeDefinition {
     descriptionMoreURL?: string;
   }>;
 }
-export type PluginDefinition<T = any> = {
+export interface PluginDefinition<T = any> {
   path?: string;
   hook: Plugin<T>;
-};
+}
 export interface TagDefinition {
   dir: string;
   filePath: string;
@@ -209,7 +209,7 @@ export function loadFileForImport(
 
 export function normalizeTemplateString(
   quasis: Array<string | t.TemplateElement>,
-  expressions: t.Expression[]
+  ...expressions: t.Expression[]
 ): t.TemplateLiteral;
 
 type Loc = { line: number; column: number; index?: number };
diff --git a/packages/compiler/config.d.ts b/packages/compiler/config.d.ts
index c30f9ac835..41cad53171 100644
--- a/packages/compiler/config.d.ts
+++ b/packages/compiler/config.d.ts
@@ -10,7 +10,10 @@ declare const Config: {
   ignoreUnrecognizedTags?: boolean;
   sourceMaps?: boolean | "inline" | "both";
   translator?: any;
-  fileSystem?: typeof import("fs");
+  fileSystem?: Pick<
+    typeof import("fs"),
+    "statSync" | "readFileSync" | "readdirSync"
+  >;
   modules?: "esm" | "cjs";
   resolveVirtualDependency?:
     | ((
diff --git a/packages/compiler/index.d.ts b/packages/compiler/index.d.ts
index 9c1e688127..5154764898 100644
--- a/packages/compiler/index.d.ts
+++ b/packages/compiler/index.d.ts
@@ -3,7 +3,8 @@ import { TaglibLookup, Diagnostic } from "@marko/babel-utils";
 import * as types from "./babel-types";
 export { types };
 
-export type Config = typeof import("./config");
+type _Config = typeof import("./config");
+export interface Config extends _Config {}
 
 type Dep = {
   type: string;
@@ -16,21 +17,21 @@ type Dep = {
   [x: string]: unknown;
 };
 
-export type MarkoMeta = {
+export interface MarkoMeta {
   id: string;
   component?: string;
   watchFiles: string[];
   tags?: string[];
   deps: Array<string | Dep>;
   diagnostics: Diagnostic[];
-};
+}
 
-export type CompileResult = {
+export interface CompileResult {
   ast: types.File;
   code: string;
   map: SourceMap;
   meta: MarkoMeta;
-};
+}
 
 export function configure(config: Config): void;