diff --git a/src/privet/auth_manager.cc b/src/privet/auth_manager.cc
index 0753a2b..66d04c4 100644
--- a/src/privet/auth_manager.cc
+++ b/src/privet/auth_manager.cc
@@ -65,14 +65,13 @@
                      ErrorPtr* error) {
   UwMacaroonCaveatType caveat_type{};
   if (!uw_macaroon_caveat_get_type_(&caveat, &caveat_type)) {
-    Error::AddTo(error, FROM_HERE, kInvalidTokenError, "Unable to get type");
-    return false;
+    return Error::AddTo(error, FROM_HERE, kInvalidTokenError,
+                        "Unable to get type");
   }
 
   if (caveat_type != type) {
-    Error::AddTo(error, FROM_HERE, kInvalidTokenError,
-                 "Unexpected caveat type");
-    return false;
+    return Error::AddTo(error, FROM_HERE, kInvalidTokenError,
+                        "Unexpected caveat type");
   }
 
   return true;
@@ -86,8 +85,8 @@
     return false;
 
   if (!uw_macaroon_caveat_get_value_uint_(&caveat, value)) {
-    Error::AddTo(error, FROM_HERE, kInvalidTokenError, "Unable to read caveat");
-    return false;
+    return Error::AddTo(error, FROM_HERE, kInvalidTokenError,
+                        "Unable to read caveat");
   }
 
   return true;
@@ -103,8 +102,8 @@
   const uint8_t* start{nullptr};
   size_t size{0};
   if (!uw_macaroon_caveat_get_value_str_(&caveat, &start, &size)) {
-    Error::AddTo(error, FROM_HERE, kInvalidTokenError, "Unable to read caveat");
-    return false;
+    return Error::AddTo(error, FROM_HERE, kInvalidTokenError,
+                        "Unable to read caveat");
   }
 
   value->assign(reinterpret_cast<const char*>(start), size);
@@ -144,8 +143,8 @@
   buffer->resize(kMaxMacaroonSize);
   if (!uw_macaroon_load_(token.data(), token.size(), buffer->data(),
                          buffer->size(), macaroon)) {
-    Error::AddTo(error, FROM_HERE, kInvalidTokenError, "Invalid token format");
-    return false;
+    return Error::AddTo(error, FROM_HERE, kInvalidTokenError,
+                        "Invalid token format");
   }
   return true;
 }
@@ -155,9 +154,8 @@
                     ErrorPtr* error) {
   CHECK_EQ(kSha256OutputSize, secret.size());
   if (!uw_macaroon_verify_(&macaroon, secret.data(), secret.size())) {
-    Error::AddTo(error, FROM_HERE, "invalid_signature",
-                 "Invalid token signature");
-    return false;
+    return Error::AddTo(error, FROM_HERE, "invalid_signature",
+                        "Invalid token signature");
   }
   return true;
 }
@@ -271,23 +269,20 @@
                   &user_id, error) ||
       !ReadCaveat(macaroon.caveats[2], kUwMacaroonCaveatTypeExpiration,
                   &expiration, error)) {
-    Error::AddTo(error, FROM_HERE, errors::kInvalidAuthorization,
-                 "Invalid token");
-    return false;
+    return Error::AddTo(error, FROM_HERE, errors::kInvalidAuthorization,
+                        "Invalid token");
   }
 
   AuthScope auth_scope{FromMacaroonScope(scope)};
   if (auth_scope == AuthScope::kNone) {
-    Error::AddTo(error, FROM_HERE, errors::kInvalidAuthorization,
-                 "Invalid token data");
-    return false;
+    return Error::AddTo(error, FROM_HERE, errors::kInvalidAuthorization,
+                        "Invalid token data");
   }
 
   base::Time time{base::Time::FromTimeT(expiration)};
   if (time < clock_->Now()) {
-    Error::AddTo(error, FROM_HERE, errors::kAuthorizationExpired,
-                 "Token is expired");
-    return false;
+    return Error::AddTo(error, FROM_HERE, errors::kAuthorizationExpired,
+                        "Token is expired");
   }
 
   if (user_info)
@@ -329,8 +324,7 @@
                      return auth.first->IsValidAuthToken(token, nullptr);
                    });
   if (claim == pending_claims_.end()) {
-    Error::AddTo(error, FROM_HERE, errors::kNotFound, "Unknown claim");
-    return false;
+    return Error::AddTo(error, FROM_HERE, errors::kNotFound, "Unknown claim");
   }
 
   SetAuthSecret(claim->first->GetAuthSecret(), claim->second);
@@ -358,8 +352,8 @@
   UwMacaroon macaroon{};
   if (!LoadMacaroon(token, &buffer, &macaroon, error) ||
       !VerifyMacaroon(auth_secret_, macaroon, error)) {
-    Error::AddTo(error, FROM_HERE, errors::kInvalidAuthCode, "Invalid token");
-    return false;
+    return Error::AddTo(error, FROM_HERE, errors::kInvalidAuthCode,
+                        "Invalid token");
   }
   return true;
 }
diff --git a/src/privet/cloud_delegate.cc b/src/privet/cloud_delegate.cc
index 0eb04e0..5f31fee 100644
--- a/src/privet/cloud_delegate.cc
+++ b/src/privet/cloud_delegate.cc
@@ -320,9 +320,8 @@
       return true;
     }
 
-    Error::AddTo(error, FROM_HERE, errors::kAccessDenied,
-                 "Need to be owner of the command.");
-    return false;
+    return Error::AddTo(error, FROM_HERE, errors::kAccessDenied,
+                        "Need to be owner of the command.");
   }
 
   provider::TaskRunner* task_runner_{nullptr};
diff --git a/src/privet/privet_handler_unittest.cc b/src/privet/privet_handler_unittest.cc
index a353a0f..fa79e77 100644
--- a/src/privet/privet_handler_unittest.cc
+++ b/src/privet/privet_handler_unittest.cc
@@ -197,11 +197,9 @@
 TEST_F(PrivetHandlerTest, ExpiredAuth) {
   auth_header_ = "Privet 123";
   EXPECT_CALL(security_, ParseAccessToken(_, _, _))
-      .WillRepeatedly(DoAll(WithArgs<2>(Invoke([](ErrorPtr* error) {
-                              Error::AddTo(error, FROM_HERE,
-                                           "authorizationExpired", "");
-                            })),
-                            Return(false)));
+      .WillRepeatedly(WithArgs<2>(Invoke([](ErrorPtr* error) {
+        return Error::AddTo(error, FROM_HERE, "authorizationExpired", "");
+      })));
   EXPECT_PRED2(IsEqualError, CodeWithReason(403, "authorizationExpired"),
                HandleRequest("/privet/info", "{}"));
 }
@@ -379,10 +377,10 @@
 
 TEST_F(PrivetHandlerTest, AuthErrorInvalidAuthCode) {
   auto set_error = [](ErrorPtr* error) {
-    Error::AddTo(error, FROM_HERE, "invalidAuthCode", "");
+    return Error::AddTo(error, FROM_HERE, "invalidAuthCode", "");
   };
   EXPECT_CALL(security_, CreateAccessToken(_, "testToken", _, _, _, _, _))
-      .WillRepeatedly(DoAll(WithArgs<6>(Invoke(set_error)), Return(false)));
+      .WillRepeatedly(WithArgs<6>(Invoke(set_error)));
   const char kInput[] = R"({
     'mode': 'pairing',
     'requestedScope': 'user',
@@ -601,10 +599,9 @@
     }
   })";
   auto set_error = [](const std::string&, const std::string&, ErrorPtr* error) {
-    Error::AddTo(error, FROM_HERE, "deviceBusy", "");
+    return Error::AddTo(error, FROM_HERE, "deviceBusy", "");
   };
-  EXPECT_CALL(wifi_, ConfigureCredentials(_, _, _))
-      .WillOnce(DoAll(Invoke(set_error), Return(false)));
+  EXPECT_CALL(wifi_, ConfigureCredentials(_, _, _)).WillOnce(Invoke(set_error));
   EXPECT_PRED2(IsEqualError, CodeWithReason(503, "deviceBusy"),
                HandleRequest("/privet/v3/setup/start", kInput));
 
@@ -641,10 +638,9 @@
   })";
 
   auto set_error = [](const std::string&, const std::string&, ErrorPtr* error) {
-    Error::AddTo(error, FROM_HERE, "deviceBusy", "");
+    return Error::AddTo(error, FROM_HERE, "deviceBusy", "");
   };
-  EXPECT_CALL(cloud_, Setup(_, _, _))
-      .WillOnce(DoAll(Invoke(set_error), Return(false)));
+  EXPECT_CALL(cloud_, Setup(_, _, _)).WillOnce(Invoke(set_error));
   EXPECT_PRED2(IsEqualError, CodeWithReason(503, "deviceBusy"),
                HandleRequest("/privet/v3/setup/start", kInput));
 
@@ -857,8 +853,7 @@
           "{'path':'comp1.comp2', 'filter':['traits', 'components']}"));
 
   auto error_handler = [](ErrorPtr* error) -> const base::DictionaryValue* {
-    Error::AddTo(error, FROM_HERE, "componentNotFound", "");
-    return nullptr;
+    return Error::AddTo(error, FROM_HERE, "componentNotFound", "");
   };
   EXPECT_CALL(cloud_, FindComponent("comp7", _))
       .WillOnce(WithArgs<1>(Invoke(error_handler)));
diff --git a/src/privet/security_manager.cc b/src/privet/security_manager.cc
index 7a3533a..358876d 100644
--- a/src/privet/security_manager.cc
+++ b/src/privet/security_manager.cc
@@ -51,9 +51,8 @@
       case crypto::P224EncryptedKeyExchange::kResultPending:
         return true;
       case crypto::P224EncryptedKeyExchange::kResultFailed:
-        Error::AddTo(error, FROM_HERE, errors::kInvalidClientCommitment,
-                     spake_.error());
-        return false;
+        return Error::AddTo(error, FROM_HERE, errors::kInvalidClientCommitment,
+                            spake_.error());
       default:
         LOG(FATAL) << "SecurityManager uses only one round trip";
     }
@@ -139,9 +138,8 @@
     base::TimeDelta* access_token_ttl,
     ErrorPtr* error) {
   auto disabled_mode = [](ErrorPtr* error) {
-    Error::AddTo(error, FROM_HERE, errors::kInvalidAuthMode,
-                 "Mode is not available");
-    return false;
+    return Error::AddTo(error, FROM_HERE, errors::kInvalidAuthMode,
+                        "Mode is not available");
   };
 
   switch (auth_type) {
@@ -154,9 +152,8 @@
       if (!IsPairingAuthSupported())
         return disabled_mode(error);
       if (!IsValidPairingCode(auth_code)) {
-        Error::AddTo(error, FROM_HERE, errors::kInvalidAuthCode,
-                     "Invalid authCode");
-        return false;
+        return Error::AddTo(error, FROM_HERE, errors::kInvalidAuthCode,
+                            "Invalid authCode");
       }
       return CreateAccessTokenImpl(auth_type, desired_scope, access_token,
                                    access_token_scope, access_token_ttl);
@@ -170,9 +167,8 @@
           error);
   }
 
-  Error::AddTo(error, FROM_HERE, errors::kInvalidAuthMode,
-               "Unsupported auth mode");
-  return false;
+  return Error::AddTo(error, FROM_HERE, errors::kInvalidAuthMode,
+                      "Unsupported auth mode");
 }
 
 bool SecurityManager::CreateAccessToken(AuthType auth_type,
@@ -290,9 +286,8 @@
   const auto& pairing_modes = GetSettings().pairing_modes;
   if (std::find(pairing_modes.begin(), pairing_modes.end(), mode) ==
       pairing_modes.end()) {
-    Error::AddTo(error, FROM_HERE, errors::kInvalidParams,
-                 "Pairing mode is not enabled");
-    return false;
+    return Error::AddTo(error, FROM_HERE, errors::kInvalidParams,
+                        "Pairing mode is not enabled");
   }
 
   std::string code;
@@ -305,9 +300,8 @@
       code = base::StringPrintf("%04i", base::RandInt(0, 9999));
       break;
     default:
-      Error::AddTo(error, FROM_HERE, errors::kInvalidParams,
-                   "Unsupported pairing mode");
-      return false;
+      return Error::AddTo(error, FROM_HERE, errors::kInvalidParams,
+                          "Unsupported pairing mode");
   }
 
   std::unique_ptr<KeyExchanger> spake;
@@ -322,9 +316,8 @@
       }
     // Fall through...
     default:
-      Error::AddTo(error, FROM_HERE, errors::kInvalidParams,
-                   "Unsupported crypto");
-      return false;
+      return Error::AddTo(error, FROM_HERE, errors::kInvalidParams,
+                          "Unsupported crypto");
   }
 
   // Allow only a single session at a time for now.
@@ -382,9 +375,8 @@
   if (!session->second->ProcessMessage(
           std::string(commitment.begin(), commitment.end()), error)) {
     ClosePendingSession(session_id);
-    Error::AddTo(error, FROM_HERE, errors::kCommitmentMismatch,
-                 "Pairing code or crypto implementation mismatch");
-    return false;
+    return Error::AddTo(error, FROM_HERE, errors::kCommitmentMismatch,
+                        "Pairing code or crypto implementation mismatch");
   }
 
   const std::string& key = session->second->GetKey();
@@ -440,9 +432,8 @@
     return true;
 
   if (block_pairing_until_ > auth_manager_->Now()) {
-    Error::AddTo(error, FROM_HERE, errors::kDeviceBusy,
-                 "Too many pairing attempts");
-    return false;
+    return Error::AddTo(error, FROM_HERE, errors::kDeviceBusy,
+                        "Too many pairing attempts");
   }
 
   if (++pairing_attemts_ >= kMaxAllowedPairingAttemts) {