diff --git a/codex-rs/core-plugins/src/remote.rs b/codex-rs/core-plugins/src/remote.rs
index a2286199e..3a6b5f6d2 100644
--- a/codex-rs/core-plugins/src/remote.rs
+++ b/codex-rs/core-plugins/src/remote.rs
@@ -27,6 +27,10 @@ mod catalog_cache;
 mod remote_installed_plugin_sync;
 mod share;
 
+#[cfg(test)]
+#[path = "remote_tests.rs"]
+mod tests;
+
 pub use remote_installed_plugin_sync::RemoteInstalledPluginBundleSyncError;
 pub use remote_installed_plugin_sync::RemoteInstalledPluginBundleSyncOutcome;
 pub use remote_installed_plugin_sync::RemotePluginCacheMutationGuard;
@@ -812,40 +816,29 @@ fn build_remote_marketplace(
     installed_plugins: Vec<RemotePluginInstalledItem>,
     include_installed_only: bool,
 ) -> Result<Option<RemoteMarketplace>, RemotePluginCatalogError> {
-    let directory_plugins = directory_plugins
-        .into_iter()
-        .map(|plugin| (plugin.id.clone(), plugin))
-        .collect::<BTreeMap<_, _>>();
-    let installed_plugins = installed_plugins
+    let mut installed_plugins = installed_plugins
         .into_iter()
         .map(|plugin| (plugin.plugin.id.clone(), plugin))
         .collect::<BTreeMap<_, _>>();
-    let plugin_ids = directory_plugins
-        .keys()
-        .chain(
-            include_installed_only
-                .then_some(&installed_plugins)
-                .into_iter()
-                .flat_map(|plugins| plugins.keys()),
-        )
-        .cloned()
-        .collect::<BTreeSet<_>>();
-    if plugin_ids.is_empty() {
+    let mut plugins = directory_plugins
+        .into_iter()
+        .map(|plugin| {
+            let installed_plugin = installed_plugins.remove(&plugin.id);
+            build_remote_plugin_summary(&plugin, installed_plugin.as_ref())
+        })
+        .collect::<Result<Vec<_>, _>>()?;
+    if include_installed_only {
+        plugins.extend(
+            installed_plugins
+                .into_values()
+                .map(|plugin| build_remote_plugin_summary(&plugin.plugin, Some(&plugin)))
+                .collect::<Result<Vec<_>, _>>()?,
+        );
+    }
+    if plugins.is_empty() {
         return Ok(None);
     }
 
-    let mut plugins = plugin_ids
-        .into_iter()
-        .filter_map(|plugin_id| {
-            let directory_plugin = directory_plugins.get(&plugin_id);
-            let installed_plugin = installed_plugins.get(&plugin_id);
-            directory_plugin
-                .or_else(|| installed_plugin.map(|plugin| &plugin.plugin))
-                .map(|plugin| (plugin, installed_plugin))
-        })
-        .map(|(plugin, installed_plugin)| build_remote_plugin_summary(plugin, installed_plugin))
-        .collect::<Result<Vec<_>, _>>()?;
-    sort_remote_plugin_summaries_by_display_name(&mut plugins);
     Ok(Some(RemoteMarketplace {
         name: name.to_string(),
         display_name: display_name.to_string(),
diff --git a/codex-rs/core-plugins/src/remote_tests.rs b/codex-rs/core-plugins/src/remote_tests.rs
new file mode 100644
index 000000000..cff134b80
--- /dev/null
+++ b/codex-rs/core-plugins/src/remote_tests.rs
@@ -0,0 +1,78 @@
+use super::*;
+use pretty_assertions::assert_eq;
+
+#[test]
+fn build_remote_marketplace_preserves_directory_order_and_appends_installed_only_plugins() {
+    let directory_plugins = vec![
+        directory_plugin("plugin-z", "zulu"),
+        directory_plugin("plugin-m", "mike"),
+    ];
+    let installed_plugins = vec![RemotePluginInstalledItem {
+        plugin: directory_plugin("plugin-a", "alpha"),
+        enabled: true,
+        disabled_skill_names: Vec::new(),
+    }];
+
+    let marketplace = build_remote_marketplace(
+        "marketplace",
+        "Marketplace",
+        directory_plugins,
+        installed_plugins,
+        /*include_installed_only*/ true,
+    )
+    .expect("marketplace should be valid")
+    .expect("marketplace should not be empty");
+
+    assert_eq!(
+        marketplace
+            .plugins
+            .into_iter()
+            .map(|plugin| plugin.remote_plugin_id)
+            .collect::<Vec<_>>(),
+        vec!["plugin-z", "plugin-m", "plugin-a"]
+    );
+}
+
+fn directory_plugin(id: &str, name: &str) -> RemotePluginDirectoryItem {
+    RemotePluginDirectoryItem {
+        id: id.to_string(),
+        name: name.to_string(),
+        scope: RemotePluginScope::Global,
+        discoverability: None,
+        creator_account_user_id: None,
+        creator_name: None,
+        share_url: None,
+        share_principals: None,
+        installation_policy: PluginInstallPolicy::Available,
+        authentication_policy: PluginAuthPolicy::OnUse,
+        availability: PluginAvailability::Available,
+        release: RemotePluginReleaseResponse {
+            version: None,
+            display_name: name.to_string(),
+            description: String::new(),
+            bundle_download_url: None,
+            app_ids: Vec::new(),
+            app_manifest: None,
+            app_templates: Vec::new(),
+            keywords: Vec::new(),
+            interface: RemotePluginReleaseInterfaceResponse {
+                short_description: None,
+                long_description: None,
+                developer_name: None,
+                category: None,
+                capabilities: Vec::new(),
+                website_url: None,
+                privacy_policy_url: None,
+                terms_of_service_url: None,
+                brand_color: None,
+                default_prompt: None,
+                default_prompts: None,
+                composer_icon_url: None,
+                logo_url: None,
+                screenshot_urls: Vec::new(),
+            },
+            skills: Vec::new(),
+            mcp_servers: Vec::new(),
+        },
+    }
+}