diff --git a/healthd/BatteryMonitor.cpp b/healthd/BatteryMonitor.cpp
index e4cf582..0c97632 100644
--- a/healthd/BatteryMonitor.cpp
+++ b/healthd/BatteryMonitor.cpp
@@ -432,7 +432,7 @@
     }
 
     if (readFromFile(mHealthdConfig->batteryTechnologyPath, &buf) > 0)
-        mHealthInfo->batteryTechnology = String8(buf.c_str());
+        mHealthInfo->batteryTechnology = buf;
 
     if (readFromFile(mHealthdConfig->chargingPolicyPath, &buf) > 0)
         mHealthInfo->chargingPolicy = getBatteryChargingPolicy(buf.c_str());
@@ -786,39 +786,35 @@
                     path.clear();
                     path.appendFormat("%s/%s/status", POWER_SUPPLY_SYSFS_PATH,
                                       name);
-                    if (access(path, R_OK) == 0)
-                        mHealthdConfig->batteryStatusPath = path;
+                    if (access(path.c_str(), R_OK) == 0) mHealthdConfig->batteryStatusPath = path;
                 }
 
                 if (mHealthdConfig->batteryHealthPath.empty()) {
                     path.clear();
                     path.appendFormat("%s/%s/health", POWER_SUPPLY_SYSFS_PATH,
                                       name);
-                    if (access(path, R_OK) == 0)
-                        mHealthdConfig->batteryHealthPath = path;
+                    if (access(path.c_str(), R_OK) == 0) mHealthdConfig->batteryHealthPath = path;
                 }
 
                 if (mHealthdConfig->batteryPresentPath.empty()) {
                     path.clear();
                     path.appendFormat("%s/%s/present", POWER_SUPPLY_SYSFS_PATH,
                                       name);
-                    if (access(path, R_OK) == 0)
-                        mHealthdConfig->batteryPresentPath = path;
+                    if (access(path.c_str(), R_OK) == 0) mHealthdConfig->batteryPresentPath = path;
                 }
 
                 if (mHealthdConfig->batteryCapacityPath.empty()) {
                     path.clear();
                     path.appendFormat("%s/%s/capacity", POWER_SUPPLY_SYSFS_PATH,
                                       name);
-                    if (access(path, R_OK) == 0)
-                        mHealthdConfig->batteryCapacityPath = path;
+                    if (access(path.c_str(), R_OK) == 0) mHealthdConfig->batteryCapacityPath = path;
                 }
 
                 if (mHealthdConfig->batteryVoltagePath.empty()) {
                     path.clear();
                     path.appendFormat("%s/%s/voltage_now",
                                       POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0) {
+                    if (access(path.c_str(), R_OK) == 0) {
                         mHealthdConfig->batteryVoltagePath = path;
                     }
                 }
@@ -827,7 +823,7 @@
                     path.clear();
                     path.appendFormat("%s/%s/charge_full",
                                       POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0)
+                    if (access(path.c_str(), R_OK) == 0)
                         mHealthdConfig->batteryFullChargePath = path;
                 }
 
@@ -835,7 +831,7 @@
                     path.clear();
                     path.appendFormat("%s/%s/current_now",
                                       POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0)
+                    if (access(path.c_str(), R_OK) == 0)
                         mHealthdConfig->batteryCurrentNowPath = path;
                 }
 
@@ -843,27 +839,29 @@
                     path.clear();
                     path.appendFormat("%s/%s/cycle_count",
                                       POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0)
+                    if (access(path.c_str(), R_OK) == 0)
                         mHealthdConfig->batteryCycleCountPath = path;
                 }
 
                 if (mHealthdConfig->batteryCapacityLevelPath.empty()) {
                     path.clear();
                     path.appendFormat("%s/%s/capacity_level", POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0) mHealthdConfig->batteryCapacityLevelPath = path;
+                    if (access(path.c_str(), R_OK) == 0) {
+                        mHealthdConfig->batteryCapacityLevelPath = path;
+                    }
                 }
 
                 if (mHealthdConfig->batteryChargeTimeToFullNowPath.empty()) {
                     path.clear();
                     path.appendFormat("%s/%s/time_to_full_now", POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0)
+                    if (access(path.c_str(), R_OK) == 0)
                         mHealthdConfig->batteryChargeTimeToFullNowPath = path;
                 }
 
                 if (mHealthdConfig->batteryFullChargeDesignCapacityUahPath.empty()) {
                     path.clear();
                     path.appendFormat("%s/%s/charge_full_design", POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0)
+                    if (access(path.c_str(), R_OK) == 0)
                         mHealthdConfig->batteryFullChargeDesignCapacityUahPath = path;
                 }
 
@@ -871,7 +869,7 @@
                     path.clear();
                     path.appendFormat("%s/%s/current_avg",
                                       POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0)
+                    if (access(path.c_str(), R_OK) == 0)
                         mHealthdConfig->batteryCurrentAvgPath = path;
                 }
 
@@ -879,7 +877,7 @@
                     path.clear();
                     path.appendFormat("%s/%s/charge_counter",
                                       POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0)
+                    if (access(path.c_str(), R_OK) == 0)
                         mHealthdConfig->batteryChargeCounterPath = path;
                 }
 
@@ -887,7 +885,7 @@
                     path.clear();
                     path.appendFormat("%s/%s/temp", POWER_SUPPLY_SYSFS_PATH,
                                       name);
-                    if (access(path, R_OK) == 0) {
+                    if (access(path.c_str(), R_OK) == 0) {
                         mHealthdConfig->batteryTemperaturePath = path;
                     }
                 }
@@ -896,19 +894,19 @@
                     path.clear();
                     path.appendFormat("%s/%s/technology",
                                       POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0)
+                    if (access(path.c_str(), R_OK) == 0)
                         mHealthdConfig->batteryTechnologyPath = path;
                 }
 
                 if (mHealthdConfig->batteryStateOfHealthPath.empty()) {
                     path.clear();
                     path.appendFormat("%s/%s/state_of_health", POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0) {
+                    if (access(path.c_str(), R_OK) == 0) {
                         mHealthdConfig->batteryStateOfHealthPath = path;
                     } else {
                         path.clear();
                         path.appendFormat("%s/%s/health_index", POWER_SUPPLY_SYSFS_PATH, name);
-                        if (access(path, R_OK) == 0)
+                        if (access(path.c_str(), R_OK) == 0)
                             mHealthdConfig->batteryStateOfHealthPath = path;
                     }
                 }
@@ -916,32 +914,36 @@
                 if (mHealthdConfig->batteryHealthStatusPath.empty()) {
                     path.clear();
                     path.appendFormat("%s/%s/health_status", POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0) mHealthdConfig->batteryHealthStatusPath = path;
+                    if (access(path.c_str(), R_OK) == 0) {
+                        mHealthdConfig->batteryHealthStatusPath = path;
+                    }
                 }
 
                 if (mHealthdConfig->batteryManufacturingDatePath.empty()) {
                     path.clear();
                     path.appendFormat("%s/%s/manufacturing_date", POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0)
+                    if (access(path.c_str(), R_OK) == 0)
                         mHealthdConfig->batteryManufacturingDatePath = path;
                 }
 
                 if (mHealthdConfig->batteryFirstUsageDatePath.empty()) {
                     path.clear();
                     path.appendFormat("%s/%s/first_usage_date", POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0) mHealthdConfig->batteryFirstUsageDatePath = path;
+                    if (access(path.c_str(), R_OK) == 0) {
+                        mHealthdConfig->batteryFirstUsageDatePath = path;
+                    }
                 }
 
                 if (mHealthdConfig->chargingStatePath.empty()) {
                     path.clear();
                     path.appendFormat("%s/%s/charging_state", POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0) mHealthdConfig->chargingStatePath = path;
+                    if (access(path.c_str(), R_OK) == 0) mHealthdConfig->chargingStatePath = path;
                 }
 
                 if (mHealthdConfig->chargingPolicyPath.empty()) {
                     path.clear();
                     path.appendFormat("%s/%s/charging_policy", POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0) mHealthdConfig->chargingPolicyPath = path;
+                    if (access(path.c_str(), R_OK) == 0) mHealthdConfig->chargingPolicyPath = path;
                 }
 
                 break;
diff --git a/healthd/BatteryMonitor_v1.cpp b/healthd/BatteryMonitor_v1.cpp
index 686c338..2e0cfc9 100644
--- a/healthd/BatteryMonitor_v1.cpp
+++ b/healthd/BatteryMonitor_v1.cpp
@@ -352,7 +352,7 @@
         mHealthInfo->batteryHealth = getBatteryHealth(buf.c_str());
 
     if (readFromFile(mHealthdConfig->batteryTechnologyPath, &buf) > 0)
-        mHealthInfo->batteryTechnology = String8(buf.c_str());
+        mHealthInfo->batteryTechnology = buf;
 
     double MaxPower = 0;
 
@@ -639,39 +639,35 @@
                     path.clear();
                     path.appendFormat("%s/%s/status", POWER_SUPPLY_SYSFS_PATH,
                                       name);
-                    if (access(path, R_OK) == 0)
-                        mHealthdConfig->batteryStatusPath = path;
+                    if (access(path.c_str(), R_OK) == 0) mHealthdConfig->batteryStatusPath = path;
                 }
 
                 if (mHealthdConfig->batteryHealthPath.empty()) {
                     path.clear();
                     path.appendFormat("%s/%s/health", POWER_SUPPLY_SYSFS_PATH,
                                       name);
-                    if (access(path, R_OK) == 0)
-                        mHealthdConfig->batteryHealthPath = path;
+                    if (access(path.c_str(), R_OK) == 0) mHealthdConfig->batteryHealthPath = path;
                 }
 
                 if (mHealthdConfig->batteryPresentPath.empty()) {
                     path.clear();
                     path.appendFormat("%s/%s/present", POWER_SUPPLY_SYSFS_PATH,
                                       name);
-                    if (access(path, R_OK) == 0)
-                        mHealthdConfig->batteryPresentPath = path;
+                    if (access(path.c_str(), R_OK) == 0) mHealthdConfig->batteryPresentPath = path;
                 }
 
                 if (mHealthdConfig->batteryCapacityPath.empty()) {
                     path.clear();
                     path.appendFormat("%s/%s/capacity", POWER_SUPPLY_SYSFS_PATH,
                                       name);
-                    if (access(path, R_OK) == 0)
-                        mHealthdConfig->batteryCapacityPath = path;
+                    if (access(path.c_str(), R_OK) == 0) mHealthdConfig->batteryCapacityPath = path;
                 }
 
                 if (mHealthdConfig->batteryVoltagePath.empty()) {
                     path.clear();
                     path.appendFormat("%s/%s/voltage_now",
                                       POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0) {
+                    if (access(path.c_str(), R_OK) == 0) {
                         mHealthdConfig->batteryVoltagePath = path;
                     }
                 }
@@ -680,7 +676,7 @@
                     path.clear();
                     path.appendFormat("%s/%s/charge_full",
                                       POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0)
+                    if (access(path.c_str(), R_OK) == 0)
                         mHealthdConfig->batteryFullChargePath = path;
                 }
 
@@ -688,7 +684,7 @@
                     path.clear();
                     path.appendFormat("%s/%s/current_now",
                                       POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0)
+                    if (access(path.c_str(), R_OK) == 0)
                         mHealthdConfig->batteryCurrentNowPath = path;
                 }
 
@@ -696,27 +692,29 @@
                     path.clear();
                     path.appendFormat("%s/%s/cycle_count",
                                       POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0)
+                    if (access(path.c_str(), R_OK) == 0)
                         mHealthdConfig->batteryCycleCountPath = path;
                 }
 
                 if (mHealthdConfig->batteryCapacityLevelPath.empty()) {
                     path.clear();
                     path.appendFormat("%s/%s/capacity_level", POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0) mHealthdConfig->batteryCapacityLevelPath = path;
+                    if (access(path.c_str(), R_OK) == 0) {
+                        mHealthdConfig->batteryCapacityLevelPath = path;
+                    }
                 }
 
                 if (mHealthdConfig->batteryChargeTimeToFullNowPath.empty()) {
                     path.clear();
                     path.appendFormat("%s/%s/time_to_full_now", POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0)
+                    if (access(path.c_str(), R_OK) == 0)
                         mHealthdConfig->batteryChargeTimeToFullNowPath = path;
                 }
 
                 if (mHealthdConfig->batteryFullChargeDesignCapacityUahPath.empty()) {
                     path.clear();
                     path.appendFormat("%s/%s/charge_full_design", POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0)
+                    if (access(path.c_str(), R_OK) == 0)
                         mHealthdConfig->batteryFullChargeDesignCapacityUahPath = path;
                 }
 
@@ -724,7 +722,7 @@
                     path.clear();
                     path.appendFormat("%s/%s/current_avg",
                                       POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0)
+                    if (access(path.c_str(), R_OK) == 0)
                         mHealthdConfig->batteryCurrentAvgPath = path;
                 }
 
@@ -732,7 +730,7 @@
                     path.clear();
                     path.appendFormat("%s/%s/charge_counter",
                                       POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0)
+                    if (access(path.c_str(), R_OK) == 0)
                         mHealthdConfig->batteryChargeCounterPath = path;
                 }
 
@@ -740,7 +738,7 @@
                     path.clear();
                     path.appendFormat("%s/%s/temp", POWER_SUPPLY_SYSFS_PATH,
                                       name);
-                    if (access(path, R_OK) == 0) {
+                    if (access(path.c_str(), R_OK) == 0) {
                         mHealthdConfig->batteryTemperaturePath = path;
                     }
                 }
@@ -749,7 +747,7 @@
                     path.clear();
                     path.appendFormat("%s/%s/technology",
                                       POWER_SUPPLY_SYSFS_PATH, name);
-                    if (access(path, R_OK) == 0)
+                    if (access(path.c_str(), R_OK) == 0)
                         mHealthdConfig->batteryTechnologyPath = path;
                 }
 
diff --git a/libutils/CallStack.cpp b/libutils/CallStack.cpp
index 4dcb35b..11f2c92 100644
--- a/libutils/CallStack.cpp
+++ b/libutils/CallStack.cpp
@@ -82,7 +82,7 @@
 
 void CallStack::print(Printer& printer) const {
     for (size_t i = 0; i < mFrameLines.size(); i++) {
-        printer.printLine(mFrameLines[i]);
+        printer.printLine(mFrameLines[i].c_str());
     }
 }
 
diff --git a/libutils/String16_test.cpp b/libutils/String16_test.cpp
index c6e6f74..6f4642e 100644
--- a/libutils/String16_test.cpp
+++ b/libutils/String16_test.cpp
@@ -33,50 +33,50 @@
 
 TEST(String16Test, FromChar16_t) {
     String16 tmp(u"Verify me");
-    EXPECT_STR16EQ(u"Verify me", tmp);
+    EXPECT_STR16EQ(u"Verify me", tmp.c_str());
 }
 
 TEST(String16Test, FromChar16_tSized) {
     String16 tmp(u"Verify me", 7);
-    EXPECT_STR16EQ(u"Verify ", tmp);
+    EXPECT_STR16EQ(u"Verify ", tmp.c_str());
 }
 
 TEST(String16Test, FromChar) {
     String16 tmp("Verify me");
-    EXPECT_STR16EQ(u"Verify me", tmp);
+    EXPECT_STR16EQ(u"Verify me", tmp.c_str());
 }
 
 TEST(String16Test, FromCharSized) {
     String16 tmp("Verify me", 7);
-    EXPECT_STR16EQ(u"Verify ", tmp);
+    EXPECT_STR16EQ(u"Verify ", tmp.c_str());
 }
 
 TEST(String16Test, Copy) {
     String16 tmp("Verify me");
     String16 another = tmp;
-    EXPECT_STR16EQ(u"Verify me", tmp);
-    EXPECT_STR16EQ(u"Verify me", another);
+    EXPECT_STR16EQ(u"Verify me", tmp.c_str());
+    EXPECT_STR16EQ(u"Verify me", another.c_str());
 }
 
 TEST(String16Test, CopyAssign) {
     String16 tmp("Verify me");
     String16 another;
     another = tmp;
-    EXPECT_STR16EQ(u"Verify me", tmp);
-    EXPECT_STR16EQ(u"Verify me", another);
+    EXPECT_STR16EQ(u"Verify me", tmp.c_str());
+    EXPECT_STR16EQ(u"Verify me", another.c_str());
 }
 
 TEST(String16Test, Move) {
     String16 tmp("Verify me");
     String16 another(std::move(tmp));
-    EXPECT_STR16EQ(u"Verify me", another);
+    EXPECT_STR16EQ(u"Verify me", another.c_str());
 }
 
 TEST(String16Test, MoveAssign) {
     String16 tmp("Verify me");
     String16 another;
     another = std::move(tmp);
-    EXPECT_STR16EQ(u"Verify me", another);
+    EXPECT_STR16EQ(u"Verify me", another.c_str());
 }
 
 TEST(String16Test, Size) {
@@ -88,27 +88,27 @@
     String16 tmp("Verify me");
     tmp.setTo(u"New content");
     EXPECT_EQ(11U, tmp.size());
-    EXPECT_STR16EQ(u"New content", tmp);
+    EXPECT_STR16EQ(u"New content", tmp.c_str());
 }
 
 TEST(String16Test, Append) {
     String16 tmp("Verify me");
     tmp.append(String16("Hello"));
     EXPECT_EQ(14U, tmp.size());
-    EXPECT_STR16EQ(u"Verify meHello", tmp);
+    EXPECT_STR16EQ(u"Verify meHello", tmp.c_str());
 }
 
 TEST(String16Test, Insert) {
     String16 tmp("Verify me");
     tmp.insert(6, u"Insert");
     EXPECT_EQ(15U, tmp.size());
-    EXPECT_STR16EQ(u"VerifyInsert me", tmp);
+    EXPECT_STR16EQ(u"VerifyInsert me", tmp.c_str());
 }
 
 TEST(String16Test, ReplaceAll) {
     String16 tmp("Verify verify Verify");
     tmp.replaceAll(u'r', u'!');
-    EXPECT_STR16EQ(u"Ve!ify ve!ify Ve!ify", tmp);
+    EXPECT_STR16EQ(u"Ve!ify ve!ify Ve!ify", tmp.c_str());
 }
 
 TEST(String16Test, Compare) {
@@ -127,8 +127,8 @@
 TEST(String16Test, StaticStringCopy) {
     StaticString16 tmp(u"Verify me");
     String16 another = tmp;
-    EXPECT_STR16EQ(u"Verify me", tmp);
-    EXPECT_STR16EQ(u"Verify me", another);
+    EXPECT_STR16EQ(u"Verify me", tmp.c_str());
+    EXPECT_STR16EQ(u"Verify me", another.c_str());
     EXPECT_TRUE(tmp.isStaticString());
     EXPECT_TRUE(another.isStaticString());
 }
@@ -136,7 +136,7 @@
 TEST(String16Test, StaticStringMove) {
     StaticString16 tmp(u"Verify me");
     String16 another(std::move(tmp));
-    EXPECT_STR16EQ(u"Verify me", another);
+    EXPECT_STR16EQ(u"Verify me", another.c_str());
     EXPECT_TRUE(another.isStaticString());
 }
 
@@ -157,7 +157,7 @@
     StaticString16 tmp(u"Verify me");
     tmp.append(String16("Hello"));
     EXPECT_EQ(14U, tmp.size());
-    EXPECT_STR16EQ(u"Verify meHello", tmp);
+    EXPECT_STR16EQ(u"Verify meHello", tmp.c_str());
     EXPECT_FALSE(tmp.isStaticString());
 }
 
@@ -165,14 +165,14 @@
     StaticString16 tmp(u"Verify me");
     tmp.insert(6, u"Insert");
     EXPECT_EQ(15U, tmp.size());
-    EXPECT_STR16EQ(u"VerifyInsert me", tmp);
+    EXPECT_STR16EQ(u"VerifyInsert me", tmp.c_str());
     EXPECT_FALSE(tmp.isStaticString());
 }
 
 TEST(String16Test, StaticStringReplaceAll) {
     StaticString16 tmp(u"Verify verify Verify");
     tmp.replaceAll(u'r', u'!');
-    EXPECT_STR16EQ(u"Ve!ify ve!ify Ve!ify", tmp);
+    EXPECT_STR16EQ(u"Ve!ify ve!ify Ve!ify", tmp.c_str());
     EXPECT_FALSE(tmp.isStaticString());
 }
 
@@ -185,17 +185,17 @@
     StaticString16 tmp(u"Verify me");
     String16 another(u"nonstatic");
     another = tmp;
-    EXPECT_STR16EQ(u"Verify me", tmp);
-    EXPECT_STR16EQ(u"Verify me", another);
+    EXPECT_STR16EQ(u"Verify me", tmp.c_str());
+    EXPECT_STR16EQ(u"Verify me", another.c_str());
 }
 
 TEST(String16Test, StringCopyAssignFromStaticString) {
     StaticString16 tmp(u"Verify me");
     String16 another(u"nonstatic");
     another = tmp;
-    EXPECT_STR16EQ(u"Verify me", another);
+    EXPECT_STR16EQ(u"Verify me", another.c_str());
     EXPECT_TRUE(another.isStaticString());
-    EXPECT_STR16EQ(u"Verify me", tmp);
+    EXPECT_STR16EQ(u"Verify me", tmp.c_str());
     EXPECT_TRUE(tmp.isStaticString());
 }
 
@@ -203,7 +203,7 @@
     StaticString16 tmp(u"Verify me");
     String16 another(u"nonstatic");
     another = std::move(tmp);
-    EXPECT_STR16EQ(u"Verify me", another);
+    EXPECT_STR16EQ(u"Verify me", another.c_str());
     EXPECT_TRUE(another.isStaticString());
 }
 
@@ -221,19 +221,19 @@
 TEST(String16Test, ValidUtf8Conversion) {
     String16 another("abcdef");
     EXPECT_EQ(6U, another.size());
-    EXPECT_STR16EQ(another, u"abcdef");
+    EXPECT_STR16EQ(another.c_str(), u"abcdef");
 }
 
 TEST(String16Test, append) {
     String16 s;
     EXPECT_EQ(OK, s.append(String16(u"foo")));
-    EXPECT_STR16EQ(u"foo", s);
+    EXPECT_STR16EQ(u"foo", s.c_str());
     EXPECT_EQ(OK, s.append(String16(u"bar")));
-    EXPECT_STR16EQ(u"foobar", s);
+    EXPECT_STR16EQ(u"foobar", s.c_str());
     EXPECT_EQ(OK, s.append(u"baz", 0));
-    EXPECT_STR16EQ(u"foobar", s);
+    EXPECT_STR16EQ(u"foobar", s.c_str());
     EXPECT_EQ(NO_MEMORY, s.append(u"baz", SIZE_MAX));
-    EXPECT_STR16EQ(u"foobar", s);
+    EXPECT_STR16EQ(u"foobar", s.c_str());
 }
 
 TEST(String16Test, insert) {
@@ -241,19 +241,19 @@
 
     // Inserting into the empty string inserts at the start.
     EXPECT_EQ(OK, s.insert(123, u"foo"));
-    EXPECT_STR16EQ(u"foo", s);
+    EXPECT_STR16EQ(u"foo", s.c_str());
 
     // Inserting zero characters at any position is okay, but won't expand the string.
     EXPECT_EQ(OK, s.insert(123, u"foo", 0));
-    EXPECT_STR16EQ(u"foo", s);
+    EXPECT_STR16EQ(u"foo", s.c_str());
 
     // Inserting past the end of a non-empty string appends.
     EXPECT_EQ(OK, s.insert(123, u"bar"));
-    EXPECT_STR16EQ(u"foobar", s);
+    EXPECT_STR16EQ(u"foobar", s.c_str());
 
     EXPECT_EQ(OK, s.insert(3, u"!"));
-    EXPECT_STR16EQ(u"foo!bar", s);
+    EXPECT_STR16EQ(u"foo!bar", s.c_str());
 
     EXPECT_EQ(NO_MEMORY, s.insert(3, u"", SIZE_MAX));
-    EXPECT_STR16EQ(u"foo!bar", s);
+    EXPECT_STR16EQ(u"foo!bar", s.c_str());
 }
diff --git a/libutils/String8_test.cpp b/libutils/String8_test.cpp
index 9c12cb1..e1fd13a 100644
--- a/libutils/String8_test.cpp
+++ b/libutils/String8_test.cpp
@@ -100,19 +100,19 @@
 TEST_F(String8Test, ValidUtf16Conversion) {
     char16_t tmp[] = u"abcdef";
     String8 valid = String8(String16(tmp));
-    EXPECT_STREQ(valid, "abcdef");
+    EXPECT_STREQ(valid.c_str(), "abcdef");
 }
 
 TEST_F(String8Test, append) {
     String8 s;
     EXPECT_EQ(OK, s.append("foo"));
-    EXPECT_STREQ("foo", s);
+    EXPECT_STREQ("foo", s.c_str());
     EXPECT_EQ(OK, s.append("bar"));
-    EXPECT_STREQ("foobar", s);
+    EXPECT_STREQ("foobar", s.c_str());
     EXPECT_EQ(OK, s.append("baz", 0));
-    EXPECT_STREQ("foobar", s);
+    EXPECT_STREQ("foobar", s.c_str());
     EXPECT_EQ(NO_MEMORY, s.append("baz", SIZE_MAX));
-    EXPECT_STREQ("foobar", s);
+    EXPECT_STREQ("foobar", s.c_str());
 }
 
 TEST_F(String8Test, removeAll) {
@@ -123,12 +123,12 @@
 
     // expect to return true and string content should remain unchanged
     EXPECT_TRUE(s.removeAll(""));
-    EXPECT_STREQ("Hello, world!", s);
+    EXPECT_STREQ("Hello, world!", s.c_str());
 
     // expect to return false
     EXPECT_FALSE(s.removeAll("x"));
-    EXPECT_STREQ("Hello, world!", s);
+    EXPECT_STREQ("Hello, world!", s.c_str());
 
     EXPECT_TRUE(s.removeAll("o"));
-    EXPECT_STREQ("Hell, wrld!", s);
+    EXPECT_STREQ("Hell, wrld!", s.c_str());
 }
diff --git a/trusty/stats/test/stats_test.cpp b/trusty/stats/test/stats_test.cpp
index 1edddeb..1d6eb34 100644
--- a/trusty/stats/test/stats_test.cpp
+++ b/trusty/stats/test/stats_test.cpp
@@ -252,20 +252,20 @@
                     ::testing::AnyOf(::testing::Eq(TrustyAtoms::TrustyAppCrashed),
                                      ::testing::Eq(TrustyAtoms::TrustyError),
                                      ::testing::Eq(TrustyAtoms::TrustyStorageError)));
-        ASSERT_STREQ(String8(vendorAtom.reverseDomainName), "google.android.trusty");
+        ASSERT_EQ(String8(vendorAtom.reverseDomainName), "google.android.trusty");
         switch (vendorAtom.atomId) {
             case TrustyAtoms::TrustyAppCrashed:
                 ++atomAppCrashedCnt;
-                ASSERT_STREQ(String8(vendorAtom.values[0].get<VendorAtomValue::stringValue>()),
-                             "5247d19b-cf09-4272-a450-3ef20dbefc14");
+                ASSERT_EQ(String8(vendorAtom.values[0].get<VendorAtomValue::stringValue>()),
+                          "5247d19b-cf09-4272-a450-3ef20dbefc14");
                 break;
             case TrustyAtoms::TrustyStorageError:
                 ++atomStorageErrorCnt;
                 ASSERT_EQ(vendorAtom.values[0].get<VendorAtomValue::intValue>(), 5);
-                ASSERT_STREQ(String8(vendorAtom.values[1].get<VendorAtomValue::stringValue>()),
-                             "5247d19b-cf09-4272-a450-3ef20dbefc14");
-                ASSERT_STREQ(String8(vendorAtom.values[2].get<VendorAtomValue::stringValue>()),
-                             "5247d19b-cf09-4272-a450-3ef20dbefc14");
+                ASSERT_EQ(String8(vendorAtom.values[1].get<VendorAtomValue::stringValue>()),
+                          "5247d19b-cf09-4272-a450-3ef20dbefc14");
+                ASSERT_EQ(String8(vendorAtom.values[2].get<VendorAtomValue::stringValue>()),
+                          "5247d19b-cf09-4272-a450-3ef20dbefc14");
                 ASSERT_EQ(vendorAtom.values[3].get<VendorAtomValue::intValue>(), 1);
                 ASSERT_EQ(vendorAtom.values[4].get<VendorAtomValue::intValue>(), 3);
                 ASSERT_EQ(vendorAtom.values[5].get<VendorAtomValue::longValue>(),
@@ -330,13 +330,13 @@
                     ::testing::AnyOf(::testing::Eq(TrustyAtoms::TrustyAppCrashed),
                                      ::testing::Eq(TrustyAtoms::TrustyError),
                                      ::testing::Eq(TrustyAtoms::TrustyStorageError)));
-        ASSERT_STREQ(String8(vendorAtom.reverseDomainName), "google.android.trusty");
+        ASSERT_EQ(String8(vendorAtom.reverseDomainName), "google.android.trusty");
 
         switch (vendorAtom.atomId) {
             case TrustyAtoms::TrustyAppCrashed:
                 ++atomAppCrashedCnt;
-                ASSERT_STREQ(String8(vendorAtom.values[0].get<VendorAtomValue::stringValue>()),
-                             kTrustyCrasherUuid);
+                ASSERT_EQ(String8(vendorAtom.values[0].get<VendorAtomValue::stringValue>()),
+                          kTrustyCrasherUuid);
                 atomCrashReasons.push_back(vendorAtom.values[1].get<VendorAtomValue::intValue>());
                 break;
             case TrustyAtoms::TrustyStorageError:
@@ -344,7 +344,7 @@
                 break;
             case TrustyAtoms::TrustyError:
                 ++atomTrustyErrorCnt;
-                ASSERT_STREQ(String8(vendorAtom.values[1].get<VendorAtomValue::stringValue>()), "");
+                ASSERT_EQ(String8(vendorAtom.values[1].get<VendorAtomValue::stringValue>()), "");
                 break;
             default:
                 FAIL() << "Unknown vendor atom ID: " << vendorAtom.atomId;