diff --git a/examples/circle_fit.cc b/examples/circle_fit.cc
index 0763806..50bba74 100644
--- a/examples/circle_fit.cc
+++ b/examples/circle_fit.cc
@@ -107,7 +107,7 @@
 };
 
 int main(int argc, char** argv) {
-  google::ParseCommandLineFlags(&argc, &argv, true);
+  CERES_GFLAGS_NAMESPACE::ParseCommandLineFlags(&argc, &argv, true);
   google::InitGoogleLogging(argv[0]);
 
   double x, y, r;