diff --git a/payload_consumer/delta_performer_integration_test.cc b/payload_consumer/delta_performer_integration_test.cc
index f0aea95..34ce0de 100644
--- a/payload_consumer/delta_performer_integration_test.cc
+++ b/payload_consumer/delta_performer_integration_test.cc
@@ -543,10 +543,12 @@
   // Extend the "partitions" holding the file system a bit.
   EXPECT_EQ(0, HANDLE_EINTR(truncate(state->a_img.c_str(),
                                      state->image_size + 1024 * 1024)));
-  EXPECT_EQ(state->image_size + 1024 * 1024, utils::FileSize(state->a_img));
+  EXPECT_EQ(static_cast<off_t>(state->image_size + 1024 * 1024),
+            utils::FileSize(state->a_img));
   EXPECT_EQ(0, HANDLE_EINTR(truncate(state->b_img.c_str(),
                                      state->image_size + 1024 * 1024)));
-  EXPECT_EQ(state->image_size + 1024 * 1024, utils::FileSize(state->b_img));
+  EXPECT_EQ(static_cast<off_t>(state->image_size + 1024 * 1024),
+            utils::FileSize(state->b_img));
 
   if (signature_test == kSignatureGeneratedPlaceholder ||
       signature_test == kSignatureGeneratedPlaceholderMismatch) {
@@ -745,7 +747,7 @@
   (*performer)->set_public_key_path(kUnittestPublicKeyPath);
   DeltaPerformerIntegrationTest::SetSupportedVersion(*performer, minor_version);
 
-  EXPECT_EQ(state->image_size,
+  EXPECT_EQ(static_cast<off_t>(state->image_size),
             HashCalculator::RawHashOfFile(
                 state->a_img,
                 state->image_size,
@@ -892,7 +894,7 @@
 
   EXPECT_EQ(state->image_size, partitions[0].target_size);
   brillo::Blob expected_new_rootfs_hash;
-  EXPECT_EQ(state->image_size,
+  EXPECT_EQ(static_cast<off_t>(state->image_size),
             HashCalculator::RawHashOfFile(state->b_img,
                                           state->image_size,
                                           &expected_new_rootfs_hash));
diff --git a/payload_consumer/download_action_unittest.cc b/payload_consumer/download_action_unittest.cc
index 51d3c3a..d12b4ae 100644
--- a/payload_consumer/download_action_unittest.cc
+++ b/payload_consumer/download_action_unittest.cc
@@ -307,7 +307,8 @@
   const off_t resulting_file_size(utils::FileSize(temp_file.GetPath()));
   EXPECT_GE(resulting_file_size, 0);
   if (resulting_file_size != 0)
-    EXPECT_EQ(kMockHttpFetcherChunkSize, resulting_file_size);
+    EXPECT_EQ(kMockHttpFetcherChunkSize,
+              static_cast<size_t>(resulting_file_size));
 }
 
 }  // namespace
diff --git a/payload_consumer/extent_writer_unittest.cc b/payload_consumer/extent_writer_unittest.cc
index efeab09..6884c0b 100644
--- a/payload_consumer/extent_writer_unittest.cc
+++ b/payload_consumer/extent_writer_unittest.cc
@@ -86,7 +86,8 @@
   EXPECT_TRUE(direct_writer.Write(bytes.data(), bytes.size()));
   EXPECT_TRUE(direct_writer.End());
 
-  EXPECT_EQ(kBlockSize + bytes.size(), utils::FileSize(path_));
+  EXPECT_EQ(static_cast<off_t>(kBlockSize + bytes.size()),
+            utils::FileSize(path_));
 
   brillo::Blob result_file;
   EXPECT_TRUE(utils::ReadFile(path_, &result_file));
@@ -153,7 +154,7 @@
   }
   EXPECT_TRUE(direct_writer.End());
 
-  EXPECT_EQ(data.size(), utils::FileSize(path_));
+  EXPECT_EQ(static_cast<off_t>(data.size()), utils::FileSize(path_));
 
   brillo::Blob result_file;
   EXPECT_TRUE(utils::ReadFile(path_, &result_file));
@@ -202,7 +203,7 @@
   ASSERT_TRUE(zero_pad_writer.Write(data.data(), bytes_to_write));
   EXPECT_TRUE(zero_pad_writer.End());
 
-  EXPECT_EQ(data.size(), utils::FileSize(path_));
+  EXPECT_EQ(static_cast<off_t>(data.size()), utils::FileSize(path_));
 
   brillo::Blob result_file;
   EXPECT_TRUE(utils::ReadFile(path_, &result_file));
@@ -251,7 +252,7 @@
   EXPECT_TRUE(direct_writer.End());
 
   // check file size, then data inside
-  ASSERT_EQ(2 * kBlockSize, utils::FileSize(path_));
+  ASSERT_EQ(static_cast<off_t>(2 * kBlockSize), utils::FileSize(path_));
 
   brillo::Blob resultant_data;
   EXPECT_TRUE(utils::ReadFile(path_, &resultant_data));