diff --git a/cas/aidl/default/TypeConvert.cpp b/cas/aidl/default/TypeConvert.cpp
index 4f7005f..1f0a46d 100644
--- a/cas/aidl/default/TypeConvert.cpp
+++ b/cas/aidl/default/TypeConvert.cpp
@@ -98,7 +98,7 @@
     for (auto it = sessionId.begin(); it != sessionId.end(); it++) {
         result.appendFormat("%02x ", *it);
     }
-    if (result.isEmpty()) {
+    if (result.empty()) {
         result.append("(null)");
     }
     return result;