diff --git a/Sources/tart/Credentials/EnvironmentCredentialsProvider.swift b/Sources/tart/Credentials/EnvironmentCredentialsProvider.swift
index 5deb949..c91e273 100644
--- a/Sources/tart/Credentials/EnvironmentCredentialsProvider.swift
+++ b/Sources/tart/Credentials/EnvironmentCredentialsProvider.swift
@@ -2,6 +2,11 @@ import Foundation
 
 class EnvironmentCredentialsProvider: CredentialsProvider {
   func retrieve(host: String) throws -> (String, String)? {
+    if let tartRegistryHostname = ProcessInfo.processInfo.environment["TART_REGISTRY_HOSTNAME"],
+       tartRegistryHostname != host {
+      return nil
+    }
+
     let username = ProcessInfo.processInfo.environment["TART_REGISTRY_USERNAME"]
     let password = ProcessInfo.processInfo.environment["TART_REGISTRY_PASSWORD"]
     if let username = username, let password = password {