diff --git a/modules/remote_bitrate_estimator/tools/bwe_rtp.cc b/modules/remote_bitrate_estimator/tools/bwe_rtp.cc
index d7cdb54d92..0e435ebe68 100644
--- a/modules/remote_bitrate_estimator/tools/bwe_rtp.cc
+++ b/modules/remote_bitrate_estimator/tools/bwe_rtp.cc
@@ -92,7 +92,7 @@ bool ParseArgsAndSetupEstimator(int argc,
     fprintf(stderr, "0x%08x, ", s);
   }
   fprintf(stderr, "\n");
-  if (filename.substr(filename.find_last_of(".")) == ".pcap") {
+  if (filename.substr(filename.find_last_of('.')) == ".pcap") {
     fprintf(stderr, "Opening as pcap\n");
     *rtp_reader = webrtc::test::RtpFileReader::Create(
         webrtc::test::RtpFileReader::kPcap, filename.c_str(),
diff --git a/p2p/base/port.cc b/p2p/base/port.cc
index f7ba6c97a4..d6e8cdd7d2 100644
--- a/p2p/base/port.cc
+++ b/p2p/base/port.cc
@@ -706,7 +706,7 @@ bool Port::ParseStunUsername(const StunMessage* stun_msg,
 
   // RFRAG:LFRAG
   const std::string username = username_attr->GetString();
-  size_t colon_pos = username.find(":");
+  size_t colon_pos = username.find(':');
   if (colon_pos == std::string::npos) {
     return false;
   }
diff --git a/pc/webrtc_sdp_unittest.cc b/pc/webrtc_sdp_unittest.cc
index 210848ff8c..7b1c50a6cd 100644
--- a/pc/webrtc_sdp_unittest.cc
+++ b/pc/webrtc_sdp_unittest.cc
@@ -2385,7 +2385,7 @@ TEST_F(WebRtcSdpTest, SerializeSessionDescriptionWithH264) {
   std::string to_find = "a=fmtp:" + pt + " ";
   size_t fmtp_pos = message.find(to_find);
   ASSERT_NE(std::string::npos, fmtp_pos) << "Failed to find " << to_find;
-  size_t fmtp_endpos = message.find("\n", fmtp_pos);
+  size_t fmtp_endpos = message.find('\n', fmtp_pos);
   ASSERT_NE(std::string::npos, fmtp_endpos);
   std::string fmtp_value = message.substr(fmtp_pos, fmtp_endpos);
   EXPECT_NE(std::string::npos, fmtp_value.find("level-asymmetry-allowed=1"));
diff --git a/rtc_base/ssl_identity.cc b/rtc_base/ssl_identity.cc
index 63818c1bb9..64c0f67297 100644
--- a/rtc_base/ssl_identity.cc
+++ b/rtc_base/ssl_identity.cc
@@ -174,7 +174,7 @@ bool SSLIdentity::PemToDer(const std::string& pem_type,
   if (header == std::string::npos) {
     return false;
   }
-  size_t body = pem_string.find("\n", header);
+  size_t body = pem_string.find('\n', header);
   if (body == std::string::npos) {
     return false;
   }
diff --git a/rtc_tools/simple_command_line_parser.cc b/rtc_tools/simple_command_line_parser.cc
index c34aa90556..f363d19b12 100644
--- a/rtc_tools/simple_command_line_parser.cc
+++ b/rtc_tools/simple_command_line_parser.cc
@@ -26,12 +26,12 @@ void CommandLineParser::Init(int argc, char** argv) {
 }
 
 bool CommandLineParser::IsStandaloneFlag(std::string flag) {
-  return flag.find("=") == std::string::npos;
+  return flag.find('=') == std::string::npos;
 }
 
 bool CommandLineParser::IsFlagWellFormed(std::string flag) {
   size_t dash_pos = flag.find("--");
-  size_t equal_pos = flag.find("=");
+  size_t equal_pos = flag.find('=');
   if (dash_pos != 0) {
     fprintf(stderr, "Wrong switch format: %s\n", flag.c_str());
     fprintf(stderr, "Flag doesn't start with --\n");
@@ -52,7 +52,7 @@ bool CommandLineParser::IsFlagWellFormed(std::string flag) {
 
 std::string CommandLineParser::GetCommandLineFlagName(std::string flag) {
   size_t dash_pos = flag.find("--");
-  size_t equal_pos = flag.find("=");
+  size_t equal_pos = flag.find('=');
   if (equal_pos == std::string::npos) {
     return flag.substr(dash_pos + 2);
   } else {
@@ -61,7 +61,7 @@ std::string CommandLineParser::GetCommandLineFlagName(std::string flag) {
 }
 
 std::string CommandLineParser::GetCommandLineFlagValue(std::string flag) {
-  size_t equal_pos = flag.find("=");
+  size_t equal_pos = flag.find('=');
   if (equal_pos == std::string::npos) {
     return "";
   } else {