diff --git a/cycle_breaker_unittest.cc b/cycle_breaker_unittest.cc
index ec7f8a3..47a6e75 100644
--- a/cycle_breaker_unittest.cc
+++ b/cycle_breaker_unittest.cc
@@ -72,7 +72,7 @@
 
 namespace {
 pair<Vertex::Index, EdgeProperties> EdgeWithWeight(Vertex::Index dest,
-uint64 weight) {
+uint64_t weight) {
   EdgeProperties props;
   props.extents.resize(1);
   props.extents[0].set_num_blocks(weight);