diff --git a/src/lib/amber.ts b/src/lib/amber.ts
index 68b7898..1c61c96 100644
--- a/src/lib/amber.ts
+++ b/src/lib/amber.ts
@@ -300,22 +300,15 @@ function buildCallbackUrl(): string {
 /**
  * Navigate to an Amber nostrsigner: URL.
  *
- * Amber has two code paths depending on how it receives the intent:
+ * Per NIP-55, web clients must navigate directly to the nostrsigner: URI
+ * using window.location.href. This fires an Android intent that Amber
+ * intercepts via its registered nostrsigner: scheme handler.
  *
- * 1. NATIVE path (no Browser.EXTRA_APPLICATION_ID): reads type from
- *    intent EXTRAS — not set when coming from a WebView URL navigation.
- *
- * 2. WEB/BROWSER path (Browser.EXTRA_APPLICATION_ID present): reads type
- *    from URL query params — set when a browser/WebView opens a URL.
- *
- * We need the WEB path. window.open('url', '_blank') causes the WebView
- * to open the URL as a browser navigation, which sets
- * Browser.EXTRA_APPLICATION_ID and routes Amber to parse our URL params.
+ * DO NOT use window.open(..., '_blank') — that opens a new tab/window
+ * instead of firing the intent, which is what caused "malformed request".
  */
 function openAmberUrl(url: string): void {
-  // _blank triggers the browser intent path in Android WebView,
-  // which sets Browser.EXTRA_APPLICATION_ID so Amber reads URL query params.
-  window.open(url, '_blank');
+  window.location.href = url;
 }
 
 /**