diff --git a/common/http_fetcher_unittest.cc b/common/http_fetcher_unittest.cc
index 91f85db..aaa538c 100644
--- a/common/http_fetcher_unittest.cc
+++ b/common/http_fetcher_unittest.cc
@@ -923,7 +923,7 @@
                const string& url,
                const vector<pair<off_t, off_t>>& ranges,
                const string& expected_prefix,
-               off_t expected_size,
+               size_t expected_size,
                HttpResponseCode expected_response_code) {
   MultiHttpFetcherTestDelegate delegate(expected_response_code);
   delegate.fetcher_.reset(fetcher_in);
diff --git a/common/utils_unittest.cc b/common/utils_unittest.cc
index 6c4e5af..24468b9 100644
--- a/common/utils_unittest.cc
+++ b/common/utils_unittest.cc
@@ -413,7 +413,8 @@
   string contents;
   EXPECT_TRUE(utils::ReadFile(path.value(), &contents));
   EXPECT_EQ(contents, expected_contents);
-  EXPECT_EQ(utils::FileSize(path.value()), expected_contents.size());
+  EXPECT_EQ(static_cast<off_t>(expected_contents.size()),
+            utils::FileSize(path.value()));
 }
 
 TEST(UtilsTest, ConvertToOmahaInstallDate) {