diff --git a/tools/aapt2/cmd/Diff.cpp b/tools/aapt2/cmd/Diff.cpp
index 423e939..5bfc732 100644
--- a/tools/aapt2/cmd/Diff.cpp
+++ b/tools/aapt2/cmd/Diff.cpp
@@ -78,7 +78,7 @@
   SymbolTable symbol_table_;
 };
 
-static void EmitDiffLine(const android::Source& source, const StringPiece& message) {
+static void EmitDiffLine(const android::Source& source, StringPiece message) {
   std::cerr << source << ": " << message << "\n";
 }