diff --git a/.changeset/funny-boats-care.md b/.changeset/funny-boats-care.md
new file mode 100644
index 0000000..9500ede
--- /dev/null
+++ b/.changeset/funny-boats-care.md
@@ -0,0 +1,13 @@
+---
+"wrangler-action": minor
+---
+
+Stop racing secret uploads
+
+For up to date versions of wrangler, secrets are uploaded via the 'secret:bulk' command, which batches updates in a single API call.
+
+For versions of wrangler without that capability, the action falls back to the single 'secret put' command for each secret. It races all these with a Promise.all()
+
+Unfortunately, the single secret API cannot handle concurrency - at best, these calls have to wait on one another, holding requests open all the while. Often it times out and errors.
+
+This fixes the legacy secret upload errors by making these calls serially instead of concurrently.
diff --git a/src/index.ts b/src/index.ts
index 576e3fd..405aa3b 100755
--- a/src/index.ts
+++ b/src/index.ts
@@ -152,24 +152,22 @@ function getEnvVar(envVar: string) {
 	return value;
 }
 
-function legacyUploadSecrets(
+async function legacyUploadSecrets(
 	secrets: string[],
 	environment?: string,
 	workingDirectory?: string,
 ) {
-	return Promise.all(
-		secrets.map((secret) => {
-			const args = ["wrangler", "secret", "put", secret];
-			if (environment) {
-				args.push("--env", environment);
-			}
-			return exec(packageManager.exec, args, {
-				cwd: workingDirectory,
-				silent: config["QUIET_MODE"],
-				input: Buffer.from(getSecret(secret)),
-			});
-		}),
-	);
+	for (const secret of secrets) {
+		const args = ["wrangler", "secret", "put", secret];
+		if (environment) {
+			args.push("--env", environment);
+		}
+		await exec(packageManager.exec, args, {
+			cwd: workingDirectory,
+			silent: config["QUIET_MODE"],
+			input: Buffer.from(getSecret(secret)),
+		});
+	}
 }
 
 async function uploadSecrets() {