diff --git a/bzip_extent_writer_unittest.cc b/bzip_extent_writer_unittest.cc
index 3f12c58..d724bc4 100644
--- a/bzip_extent_writer_unittest.cc
+++ b/bzip_extent_writer_unittest.cc
@@ -21,7 +21,7 @@
 
 namespace {
 const char kPathTemplate[] = "./BzipExtentWriterTest-file.XXXXXX";
-const uint32 kBlockSize = 4096;
+const uint32_t kBlockSize = 4096;
 }
 
 class BzipExtentWriterTest : public ::testing::Test {