diff --git a/src/ssb.c b/src/ssb.c
index 025936dc..9deb3009 100644
--- a/src/ssb.c
+++ b/src/ssb.c
@@ -536,7 +536,7 @@ static bool _tf_ssb_verify_and_strip_signature_internal(JSContext* context, JSVa
 		}
 		else
 		{
-			printf("base64 decode sig fail\n");
+			printf("base64 decode sig fail [%.*s]\n", (int)(sigkind - str), str);
 		}
 	}
 	else