diff --git a/scripts/test-gateway.mjs b/scripts/test-gateway.mjs
index 83fff12c..47bb3d3f 100644
--- a/scripts/test-gateway.mjs
+++ b/scripts/test-gateway.mjs
@@ -25,6 +25,16 @@ function composeArgs(projectName, args) {
   return ["compose", "-p", projectName, ...args];
 }
 
+function usesWindowsPathSyntax(filePath) {
+  return /^[A-Za-z]:($|[\\/])/.test(filePath) || filePath.startsWith("\\\\") || filePath.includes("\\");
+}
+
+function pathForInputs(...filePaths) {
+  const hasWindowsPath = filePaths.some((filePath) => usesWindowsPathSyntax(String(filePath || "")));
+
+  return hasWindowsPath ? path.win32 : path;
+}
+
 async function resolveRootDir(scriptPath) {
   const cwd = process.cwd();
 
@@ -66,21 +76,13 @@ export function resolveComposeProjectName(rootDir, env = process.env) {
     return explicit;
   }
 
-  return path.basename(rootDir);
+  return pathForInputs(rootDir).basename(rootDir);
 }
 
 export function resolveComposeNetworkName(rootDir, env = process.env) {
   return `${resolveComposeProjectName(rootDir, env)}_default`;
 }
 
-function usesWindowsPathSyntax(filePath) {
-  return /^[A-Za-z]:[\\/]/.test(filePath) || filePath.startsWith("\\\\");
-}
-
-function pathForInputs(...filePaths) {
-  return filePaths.some((filePath) => usesWindowsPathSyntax(String(filePath || ""))) ? path.win32 : path;
-}
-
 export function resolveConfigDirectory(rootDir, explicitDir = null) {
   const pathModule = pathForInputs(rootDir, explicitDir);
 
diff --git a/scripts/test-gateway.test.mjs b/scripts/test-gateway.test.mjs
index 1441a8f6..254fb9b7 100644
--- a/scripts/test-gateway.test.mjs
+++ b/scripts/test-gateway.test.mjs
@@ -25,6 +25,10 @@ test("resolveComposeProjectName falls back to backend directory name", () => {
   assert.equal(resolveComposeProjectName("C:/Users/test/backend-php", {}), "backend-php");
 });
 
+test("resolveComposeProjectName supports Windows backslash paths", () => {
+  assert.equal(resolveComposeProjectName("C:\\Users\\test\\backend-php", {}), "backend-php");
+});
+
 test("resolveComposeNetworkName derives the default compose network", () => {
   assert.equal(
     resolveComposeNetworkName("C:/Users/test/backend-php", { COMPOSE_PROJECT_NAME: "custom-stack" }),
@@ -39,6 +43,20 @@ test("resolveConfigDirectory uses the default temp folder when none is provided"
   );
 });
 
+test("resolveConfigDirectory supports Windows backslash paths", () => {
+  assert.equal(
+    resolveConfigDirectory("C:\\Users\\test\\backend-php"),
+    "C:\\Users\\test\\backend-php\\.tmp\\test-gateway"
+  );
+});
+
+test("resolveConfigDirectory supports explicit Windows absolute paths", () => {
+  assert.equal(
+    resolveConfigDirectory("/workspace/api", "C:\\Users\\test\\gateway-config"),
+    "C:\\Users\\test\\gateway-config"
+  );
+});
+
 test("shouldClaimGateway requires a token when no credentials are present", () => {
   assert.equal(shouldClaimGateway({}, ""), true);
   assert.equal(shouldClaimGateway({ gatewayId: 12, agentToken: "secret" }, ""), false);