diff --git a/packages/core/integration-tests/test/integration/ts-types/windows-paths/expected.d.ts b/packages/core/integration-tests/test/integration/ts-types/windows-paths/expected.d.ts
new file mode 100644
index 00000000000..a1dcb1c62bc
--- /dev/null
+++ b/packages/core/integration-tests/test/integration/ts-types/windows-paths/expected.d.ts
@@ -0,0 +1,18 @@
+type Params = {
+    hello: number;
+};
+interface Hello {
+    yo: string;
+}
+export class Test {
+    test(hello: Hello): string;
+}
+export function test(params: Params): number;
+export function foo(): number;
+export var x: number;
+export var hi: number;
+export declare module mod {
+    function bar(): number;
+}
+
+//# sourceMappingURL=types.d.ts.map
diff --git a/packages/core/integration-tests/test/integration/ts-types/windows-paths/index.ts b/packages/core/integration-tests/test/integration/ts-types/windows-paths/index.ts
new file mode 100644
index 00000000000..cba18435457
--- /dev/null
+++ b/packages/core/integration-tests/test/integration/ts-types/windows-paths/index.ts
@@ -0,0 +1 @@
+export * from './src/index';
diff --git a/packages/core/integration-tests/test/integration/ts-types/windows-paths/package.json b/packages/core/integration-tests/test/integration/ts-types/windows-paths/package.json
new file mode 100644
index 00000000000..e7879334bc0
--- /dev/null
+++ b/packages/core/integration-tests/test/integration/ts-types/windows-paths/package.json
@@ -0,0 +1,6 @@
+{
+  "name": "ts-types-main",
+  "private": true,
+  "main": "dist/main.js",
+  "types": "dist/types.d.ts"
+}
\ No newline at end of file
diff --git a/packages/core/integration-tests/test/integration/ts-types/windows-paths/src/index.ts b/packages/core/integration-tests/test/integration/ts-types/windows-paths/src/index.ts
new file mode 100644
index 00000000000..ba2131c36da
--- /dev/null
+++ b/packages/core/integration-tests/test/integration/ts-types/windows-paths/src/index.ts
@@ -0,0 +1,31 @@
+type Params = {
+  hello: number;
+};
+
+interface Hello {
+  yo: string;
+}
+
+export class Test {
+  test(hello: Hello) {
+    return hello.yo;
+  }
+}
+
+export function test(params: Params) {
+  return params.hello;
+}
+
+export function foo() {
+  return 2;
+}
+
+var x = 2;
+var p = x + 2, q = 3;
+export {p as hi, x};
+
+export module mod {
+  export function bar() {
+    return 2;
+  }
+}
diff --git a/packages/core/integration-tests/test/integration/ts-types/windows-paths/tsconfig.json b/packages/core/integration-tests/test/integration/ts-types/windows-paths/tsconfig.json
new file mode 100644
index 00000000000..68dcab57b6b
--- /dev/null
+++ b/packages/core/integration-tests/test/integration/ts-types/windows-paths/tsconfig.json
@@ -0,0 +1,9 @@
+{
+  "compilerOptions": {
+    "removeComments": true,
+    "baseUrl": ".",
+    "paths": {
+      "@parcel/*": ["../../*"]
+    }
+  }
+}
diff --git a/packages/core/integration-tests/test/integration/ts-types/windows-paths/yarn.lock b/packages/core/integration-tests/test/integration/ts-types/windows-paths/yarn.lock
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/packages/core/integration-tests/test/ts-types.js b/packages/core/integration-tests/test/ts-types.js
index 8a8e02324d0..957aafae66b 100644
--- a/packages/core/integration-tests/test/ts-types.js
+++ b/packages/core/integration-tests/test/ts-types.js
@@ -388,4 +388,26 @@ describe('typescript types', function () {
     );
     assert.equal(dist, expected);
   });
+
+  it('should handle a tsconfig file with paths on windows', async function () {
+    await bundle(
+      path.join(__dirname, '/integration/ts-types/windows-paths/index.ts'),
+    );
+
+    let dist = (
+      await outputFS.readFile(
+        path.join(
+          __dirname,
+          '/integration/ts-types/windows-paths/dist/types.d.ts',
+        ),
+        'utf8',
+      )
+    ).replace(/\r\n/g, '\n');
+
+    let expected = await inputFS.readFile(
+      path.join(__dirname, '/integration/ts-types/windows-paths/expected.d.ts'),
+      'utf8',
+    );
+    assert.equal(dist, expected);
+  });
 });
diff --git a/packages/transformers/typescript-types/package.json b/packages/transformers/typescript-types/package.json
index 86ef0125087..fb25bb9e6e3 100644
--- a/packages/transformers/typescript-types/package.json
+++ b/packages/transformers/typescript-types/package.json
@@ -24,6 +24,7 @@
     "@parcel/plugin": "2.6.0",
     "@parcel/source-map": "^2.0.0",
     "@parcel/ts-utils": "2.6.0",
+    "@parcel/utils": "2.6.0",
     "nullthrows": "^1.1.1"
   },
   "devDependencies": {
diff --git a/packages/transformers/typescript-types/src/TSTypesTransformer.js b/packages/transformers/typescript-types/src/TSTypesTransformer.js
index 19f3c3747b5..80473191db4 100644
--- a/packages/transformers/typescript-types/src/TSTypesTransformer.js
+++ b/packages/transformers/typescript-types/src/TSTypesTransformer.js
@@ -8,6 +8,7 @@ import type {CompilerOptions} from 'typescript';
 
 import ts from 'typescript';
 import {CompilerHost, loadTSConfig} from '@parcel/ts-utils';
+import {normalizeSeparators} from '@parcel/utils';
 import {escapeMarkdown} from '@parcel/diagnostic';
 import {TSModuleGraph} from './TSModuleGraph';
 import nullthrows from 'nullthrows';
@@ -51,9 +52,11 @@ export default (new Transformer({
       }
     }
 
-    let mainModuleName = path
-      .relative(program.getCommonSourceDirectory(), asset.filePath)
-      .slice(0, -path.extname(asset.filePath).length);
+    let mainModuleName = normalizeSeparators(
+      path
+        .relative(program.getCommonSourceDirectory(), asset.filePath)
+        .slice(0, -path.extname(asset.filePath).length),
+    );
     let moduleGraph = new TSModuleGraph(mainModuleName);
 
     let emitResult = program.emit(undefined, undefined, undefined, true, {