diff --git a/opengl/tests/hwc/hwcRects.cpp b/opengl/tests/hwc/hwcRects.cpp
index 69e56ff..5956366 100644
--- a/opengl/tests/hwc/hwcRects.cpp
+++ b/opengl/tests/hwc/hwcRects.cpp
@@ -170,7 +170,7 @@
 static EGLint width, height;
 
 // Function prototypes
-static Rectangle parseRect(string rectStr);
+static Rectangle parseRect(const string& rectStr);
 void init(void);
 void printSyntax(const char *cmd);
 
@@ -358,7 +358,7 @@
 
 // Parse string description of rectangle and add it to list of rectangles
 // to be rendered.
-static Rectangle parseRect(string rectStr)
+static Rectangle parseRect(const string& rectStr)
 {
     int rv;
     string str;