diff --git a/dist/index.js b/dist/index.js
index 92d8aec2..4ab134b3 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -92603,6 +92603,7 @@ const PLATFORM = (() => {
 const CYGWIN_MIRROR = "https://cygwin.mirror.constant.com/";
 // [HACK] https://github.com/ocaml/setup-ocaml/pull/55
 const CYGWIN_ROOT = external_node_path_namespaceObject.join("D:", "cygwin");
+const CYGWIN_ROOT_BIN = external_node_path_namespaceObject.join(CYGWIN_ROOT, "bin");
 const DUNE_CACHE_ROOT = (() => {
     const homeDir = external_node_os_.homedir();
     if (PLATFORM === "windows") {
@@ -110570,9 +110571,12 @@ async function installer() {
         });
     }
     const { opamCacheHit, cygwinCacheHit } = await restoreOpamCaches();
-    if (!cygwinCacheHit && PLATFORM === "windows") {
-        await setupCygwin();
-        await saveCygwinCache();
+    if (PLATFORM === "windows") {
+        if (!cygwinCacheHit) {
+            await setupCygwin();
+            await saveCygwinCache();
+        }
+        lib_core.addPath(CYGWIN_ROOT_BIN);
     }
     await setupOpam();
     await repositoryRemoveAll();
diff --git a/dist/post/index.js b/dist/post/index.js
index a0b76642..385d17bd 100644
--- a/dist/post/index.js
+++ b/dist/post/index.js
@@ -84737,6 +84737,7 @@ const constants_PLATFORM = (() => {
 const constants_CYGWIN_MIRROR = "https://cygwin.mirror.constant.com/";
 // [HACK] https://github.com/ocaml/setup-ocaml/pull/55
 const constants_CYGWIN_ROOT = external_node_path_namespaceObject.join("D:", "cygwin");
+const CYGWIN_ROOT_BIN = external_node_path_namespaceObject.join(constants_CYGWIN_ROOT, "bin");
 const DUNE_CACHE_ROOT = (() => {
     const homeDir = external_node_os_.homedir();
     if (constants_PLATFORM === "windows") {
diff --git a/packages/setup-ocaml/src/constants.ts b/packages/setup-ocaml/src/constants.ts
index 88b0a458..2537e928 100644
--- a/packages/setup-ocaml/src/constants.ts
+++ b/packages/setup-ocaml/src/constants.ts
@@ -52,6 +52,8 @@ export const CYGWIN_MIRROR = "https://cygwin.mirror.constant.com/";
 // [HACK] https://github.com/ocaml/setup-ocaml/pull/55
 export const CYGWIN_ROOT = path.join("D:", "cygwin");
 
+export const CYGWIN_ROOT_BIN = path.join(CYGWIN_ROOT, "bin");
+
 export const DUNE_CACHE_ROOT = (() => {
   const homeDir = os.homedir();
   if (PLATFORM === "windows") {
diff --git a/packages/setup-ocaml/src/installer.ts b/packages/setup-ocaml/src/installer.ts
index 494d4a44..8dee613d 100644
--- a/packages/setup-ocaml/src/installer.ts
+++ b/packages/setup-ocaml/src/installer.ts
@@ -9,6 +9,7 @@ import {
   saveOpamCache,
 } from "./cache.js";
 import {
+  CYGWIN_ROOT_BIN,
   DUNE_CACHE,
   DUNE_CACHE_ROOT,
   OCAML_COMPILER,
@@ -62,9 +63,12 @@ export async function installer() {
     );
   }
   const { opamCacheHit, cygwinCacheHit } = await restoreOpamCaches();
-  if (!cygwinCacheHit && PLATFORM === "windows") {
-    await setupCygwin();
-    await saveCygwinCache();
+  if (PLATFORM === "windows") {
+    if (!cygwinCacheHit) {
+      await setupCygwin();
+      await saveCygwinCache();
+    }
+    core.addPath(CYGWIN_ROOT_BIN);
   }
   await setupOpam();
   await repositoryRemoveAll();