diff --git a/index.ts b/index.ts
index c6690b2..2fedef4 100644
--- a/index.ts
+++ b/index.ts
@@ -1,4 +1,7 @@
 import {Result} from 'result'
+import logger from 'log'
+
+const log = logger('misc')
 
 export function a2str(buf: Uint8Array) : string {
     // @ts-ignore
@@ -18,9 +21,14 @@ export function a2b64(buf: Uint8Array) : string {
     return btoa(a2str(buf))
 }
 export function b642a(b64: string) : Result<Uint8Array> {
+    log.trace('b642a')
+
     try {
         return Result.ok(str2a(atob(b64)))
-    } catch (e) {}
+    } catch (e) {
+        log.warn('b64 decode failed')
+        log.debug(`error : ${e}`)
+    }
 
     return Result.error([])
 }