diff --git a/crash_reporter/crash_collector_test.cc b/crash_reporter/crash_collector_test.cc
index 90a209d..7146638 100644
--- a/crash_reporter/crash_collector_test.cc
+++ b/crash_reporter/crash_collector_test.cc
@@ -74,10 +74,11 @@
 TEST_F(CrashCollectorTest, WriteNewFile) {
   FilePath test_file = test_dir_.path().Append("test_new");
   const char kBuffer[] = "buffer";
-  EXPECT_EQ(strlen(kBuffer),
-            collector_.WriteNewFile(test_file,
-                                    kBuffer,
-                                    strlen(kBuffer)));
+  unsigned int numBytesWritten = collector_.WriteNewFile(
+      test_file,
+      kBuffer,
+      strlen(kBuffer));
+  EXPECT_EQ(strlen(kBuffer), numBytesWritten);
   EXPECT_LT(collector_.WriteNewFile(test_file,
                                     kBuffer,
                                     strlen(kBuffer)), 0);
diff --git a/crash_reporter/kernel_collector_test.cc b/crash_reporter/kernel_collector_test.cc
index 015f624..60fd832 100644
--- a/crash_reporter/kernel_collector_test.cc
+++ b/crash_reporter/kernel_collector_test.cc
@@ -49,7 +49,9 @@
  protected:
   void WriteStringToFile(const FilePath &file_path,
                          const char *data) {
-    ASSERT_EQ(strlen(data), base::WriteFile(file_path, data, strlen(data)));
+    unsigned int numBytesWritten =
+        base::WriteFile(file_path, data, strlen(data));
+    ASSERT_EQ(strlen(data), numBytesWritten);
   }
 
   void SetUpSuccessfulCollect();
@@ -284,7 +286,7 @@
   size_t end_pos = filename.find_first_of("\n");
   ASSERT_NE(std::string::npos, end_pos);
   filename = filename.substr(0, end_pos);
-  ASSERT_EQ(0, filename.find(test_crash_directory().value()));
+  ASSERT_EQ(0U, filename.find(test_crash_directory().value()));
   ASSERT_TRUE(base::PathExists(FilePath(filename)));
   std::string contents;
   ASSERT_TRUE(base::ReadFileToString(FilePath(filename), &contents));
diff --git a/crash_reporter/unclean_shutdown_collector_test.cc b/crash_reporter/unclean_shutdown_collector_test.cc
index 56d2704..36372ae 100644
--- a/crash_reporter/unclean_shutdown_collector_test.cc
+++ b/crash_reporter/unclean_shutdown_collector_test.cc
@@ -73,7 +73,9 @@
  protected:
   void WriteStringToFile(const FilePath &file_path,
                          const char *data) {
-    ASSERT_EQ(strlen(data), base::WriteFile(file_path, data, strlen(data)));
+    unsigned int numBytesWritten =
+        base::WriteFile(file_path, data, strlen(data));
+    ASSERT_EQ(strlen(data), numBytesWritten);
   }
 
   UncleanShutdownCollectorMock collector_;
diff --git a/crash_reporter/user_collector_test.cc b/crash_reporter/user_collector_test.cc
index d9c9a5b..6097286 100644
--- a/crash_reporter/user_collector_test.cc
+++ b/crash_reporter/user_collector_test.cc
@@ -101,15 +101,15 @@
       &pid, &signal, &uid, &gid, &exec_name));
   EXPECT_EQ(123456, pid);
   EXPECT_EQ(11, signal);
-  EXPECT_EQ(1000, uid);
-  EXPECT_EQ(2000, gid);
+  EXPECT_EQ(1000U, uid);
+  EXPECT_EQ(2000U, gid);
   EXPECT_EQ("foobar", exec_name);
   EXPECT_TRUE(collector_.ParseCrashAttributes("4321:6:barfoo",
       &pid, &signal, &uid, &gid, &exec_name));
   EXPECT_EQ(4321, pid);
   EXPECT_EQ(6, signal);
-  EXPECT_EQ(-1, uid);
-  EXPECT_EQ(-1, gid);
+  EXPECT_EQ(-1U, uid);
+  EXPECT_EQ(-1U, gid);
   EXPECT_EQ("barfoo", exec_name);
 
   EXPECT_FALSE(collector_.ParseCrashAttributes("123456:11",
@@ -333,8 +333,8 @@
   gid_t gid = 100;
   uid_t uid = 100;
   EXPECT_TRUE(collector_.GetUserInfoFromName("root", &uid, &gid));
-  EXPECT_EQ(0, uid);
-  EXPECT_EQ(0, gid);
+  EXPECT_EQ(0U, uid);
+  EXPECT_EQ(0U, gid);
 }
 
 TEST_F(UserCollectorTest, CopyOffProcFilesBadPath) {
@@ -387,7 +387,9 @@
 
   // maps file is not empty
   const char data[] = "test data";
-  ASSERT_EQ(sizeof(data), base::WriteFile(maps_file, data, sizeof(data)));
+  unsigned int numBytesWritten =
+      base::WriteFile(maps_file, data, sizeof(data));
+  ASSERT_EQ(sizeof(data), numBytesWritten);
   ASSERT_TRUE(base::PathExists(maps_file));
   EXPECT_TRUE(collector_.ValidateProcFiles(container_dir));
 }