diff --git a/libcef/browser/devtools/devtools_util.cc b/libcef/browser/devtools/devtools_util.cc
index 7b60a5c75..d0d7799a5 100644
--- a/libcef/browser/devtools/devtools_util.cc
+++ b/libcef/browser/devtools/devtools_util.cc
@@ -30,7 +30,7 @@ bool ParseEvent(const base::StringPiece& message,
 
   const size_t method_start = sizeof(kMethodStart) - 1;
   const size_t method_end = message.find(kMethodEnd, method_start);
-  if (method_end < 0U)
+  if (method_end == base::StringPiece::npos)
     return false;
   method = message.substr(method_start, method_end - method_start);
   if (method.empty())
@@ -77,7 +77,7 @@ bool ParseResult(const base::StringPiece& message,
 
   const size_t id_start = sizeof(kIdStart) - 1;
   const size_t id_end = message.find(kIdEnd, id_start);
-  if (id_end < 0U)
+  if (id_end == base::StringPiece::npos)
     return false;
   const base::StringPiece& id_str = message.substr(id_start, id_end - id_start);
   if (id_str.empty() || !base::StringToInt(id_str, &message_id))
diff --git a/libcef/browser/devtools/devtools_util_unittest.cc b/libcef/browser/devtools/devtools_util_unittest.cc
index 9617f9445..ec41edef2 100644
--- a/libcef/browser/devtools/devtools_util_unittest.cc
+++ b/libcef/browser/devtools/devtools_util_unittest.cc
@@ -83,7 +83,7 @@ TEST(DevToolsUtil, ProtocolParser_Initialize_IsEvent) {
   EXPECT_TRUE(parser.Initialize(message));
   EXPECT_TRUE(parser.IsInitialized());
   EXPECT_TRUE(parser.IsEvent());
-  EXPECT_STREQ("Test.myMethod", parser.method_.data());
+  EXPECT_EQ("Test.myMethod", parser.method_);
   EXPECT_TRUE(parser.params_.empty());
 
   parser.Reset();
@@ -94,8 +94,8 @@ TEST(DevToolsUtil, ProtocolParser_Initialize_IsEvent) {
   EXPECT_TRUE(parser.Initialize(message));
   EXPECT_TRUE(parser.IsInitialized());
   EXPECT_TRUE(parser.IsEvent());
-  EXPECT_STREQ("Test.myMethod2", parser.method_.data());
-  EXPECT_STREQ("{}", parser.params_.data());
+  EXPECT_EQ("Test.myMethod2", parser.method_);
+  EXPECT_EQ("{}", parser.params_);
 
   parser.Reset();
   EXPECT_FALSE(parser.IsInitialized());
@@ -105,8 +105,8 @@ TEST(DevToolsUtil, ProtocolParser_Initialize_IsEvent) {
   EXPECT_TRUE(parser.Initialize(message));
   EXPECT_TRUE(parser.IsInitialized());
   EXPECT_TRUE(parser.IsEvent());
-  EXPECT_STREQ("Test.myMethod3", parser.method_.data());
-  EXPECT_STREQ("{\"foo\":\"bar\"}", parser.params_.data());
+  EXPECT_EQ("Test.myMethod3", parser.method_);
+  EXPECT_EQ("{\"foo\":\"bar\"}", parser.params_);
 }
 
 TEST(DevToolsUtil, ProtocolParser_Initialize_IsFailure_ResultMalformed) {
@@ -162,7 +162,7 @@ TEST(DevToolsUtil, ProtocolParser_Initialize_IsResult_Result) {
   EXPECT_TRUE(parser.IsResult());
   EXPECT_EQ(1, parser.message_id_);
   EXPECT_TRUE(parser.success_);
-  EXPECT_STREQ("{}", parser.params_.data());
+  EXPECT_EQ("{}", parser.params_);
 
   parser.Reset();
   EXPECT_FALSE(parser.IsInitialized());
@@ -174,7 +174,7 @@ TEST(DevToolsUtil, ProtocolParser_Initialize_IsResult_Result) {
   EXPECT_TRUE(parser.IsResult());
   EXPECT_EQ(2, parser.message_id_);
   EXPECT_TRUE(parser.success_);
-  EXPECT_STREQ("{\"foo\":\"bar\"}", parser.params_.data());
+  EXPECT_EQ("{\"foo\":\"bar\"}", parser.params_);
 }
 
 TEST(DevToolsUtil, ProtocolParser_Initialize_IsResult_Error) {
@@ -188,7 +188,7 @@ TEST(DevToolsUtil, ProtocolParser_Initialize_IsResult_Error) {
   EXPECT_TRUE(parser.IsResult());
   EXPECT_EQ(1, parser.message_id_);
   EXPECT_FALSE(parser.success_);
-  EXPECT_STREQ("{}", parser.params_.data());
+  EXPECT_EQ("{}", parser.params_);
 
   parser.Reset();
   EXPECT_FALSE(parser.IsInitialized());
@@ -200,5 +200,21 @@ TEST(DevToolsUtil, ProtocolParser_Initialize_IsResult_Error) {
   EXPECT_TRUE(parser.IsResult());
   EXPECT_EQ(2, parser.message_id_);
   EXPECT_FALSE(parser.success_);
-  EXPECT_STREQ("{\"foo\":\"bar\"}", parser.params_.data());
+  EXPECT_EQ("{\"foo\":\"bar\"}", parser.params_);
+}
+
+TEST(DevToolsUtil, ProtocolParser_Can_Handle_MissingQuote) {
+  ProtocolParser parser;
+
+  const auto message = "{\"method\":\"Test.myMethod}";
+  EXPECT_TRUE(parser.Initialize(message));
+  EXPECT_TRUE(parser.IsFailure());
+}
+
+TEST(DevToolsUtil, ProtocolParser_Can_Handle_MissingComma) {
+  ProtocolParser parser;
+
+  const auto message = "{\"id\":1\"error\":{}}";
+  EXPECT_TRUE(parser.Initialize(message));
+  EXPECT_TRUE(parser.IsFailure());
 }