diff --git a/apps/android/app/src/main/java/ai/openclaw/android/node/DebugHandler.kt b/apps/android/app/src/main/java/ai/openclaw/android/node/DebugHandler.kt
index 49502bd3631..2b0fc04e437 100644
--- a/apps/android/app/src/main/java/ai/openclaw/android/node/DebugHandler.kt
+++ b/apps/android/app/src/main/java/ai/openclaw/android/node/DebugHandler.kt
@@ -62,7 +62,8 @@ class DebugHandler(
         results.add("Signature.Ed25519: FAILED - ${e.javaClass.simpleName}: ${e.message}")
       }
 
-      return GatewaySession.InvokeResult.ok("""{"diagnostics":"${results.joinToString("\\n").replace("\"", "\\\"")}"}"""")
+      val diagnostics = results.joinToString("\n")
+      return GatewaySession.InvokeResult.ok("""{"diagnostics":${JsonPrimitive(diagnostics)}}""")
     } catch (e: Throwable) {
       return GatewaySession.InvokeResult.error(code = "ED25519_TEST_FAILED", message = "${e.javaClass.simpleName}: ${e.message}\n${e.stackTraceToString().take(500)}")
     }