diff --git a/libs/binder/Parcel.cpp b/libs/binder/Parcel.cpp
index 4b7af45..3711362 100644
--- a/libs/binder/Parcel.cpp
+++ b/libs/binder/Parcel.cpp
@@ -683,7 +683,7 @@
     return err;
 }
 
-int Parcel::compareData(const Parcel& other) {
+int Parcel::compareData(const Parcel& other) const {
     size_t size = dataSize();
     if (size != other.dataSize()) {
         return size < other.dataSize() ? -1 : 1;