diff --git a/cpp/src/phonenumbers/stringutil.cc b/cpp/src/phonenumbers/stringutil.cc
index f455df91e..01db9eb45 100644
--- a/cpp/src/phonenumbers/stringutil.cc
+++ b/cpp/src/phonenumbers/stringutil.cc
@@ -27,7 +27,7 @@ namespace phonenumbers {
 using std::equal;
 using std::stringstream;
 
-string operator+(const string& s, int n) {
+string operator+(const string& s, int n) {  // NOLINT(runtime/string)
   stringstream stream;
 
   stream << s << n;
@@ -171,23 +171,23 @@ int GlobalReplaceSubstring(const string& substring,
 
 // StringHolder class
 
-StringHolder::StringHolder(const string& s) :
-  string_(&s),
-  cstring_(NULL),
-  len_(s.size())
+StringHolder::StringHolder(const string& s)
+  : string_(&s),
+    cstring_(NULL),
+    len_(s.size())
 {}
 
-StringHolder::StringHolder(const char* s) :
-  string_(NULL),
-  cstring_(s),
-  len_(std::strlen(s))
+StringHolder::StringHolder(const char* s)
+  : string_(NULL),
+    cstring_(s),
+    len_(std::strlen(s))
 {}
 
-StringHolder::StringHolder(uint64 n) :
-  converted_string_(SimpleItoa(n)),
-  string_(&converted_string_),
-  cstring_(NULL),
-  len_(converted_string_.length())
+StringHolder::StringHolder(uint64 n)
+  : converted_string_(SimpleItoa(n)),
+    string_(&converted_string_),
+    cstring_(NULL),
+    len_(converted_string_.length())
 {}
 
 StringHolder::~StringHolder() {}
diff --git a/cpp/src/phonenumbers/stringutil.h b/cpp/src/phonenumbers/stringutil.h
index c4f3a6fd3..48a256c39 100644
--- a/cpp/src/phonenumbers/stringutil.h
+++ b/cpp/src/phonenumbers/stringutil.h
@@ -30,7 +30,7 @@ using std::string;
 using std::vector;
 
 // Supports string("hello") + 10.
-string operator+(const string& s, int n);
+string operator+(const string& s, int n);  // NOLINT(runtime/string)
 
 // Converts integer to string.
 string SimpleItoa(uint64 n);
@@ -76,11 +76,11 @@ int GlobalReplaceSubstring(const string& substring, const string& replacement,
 // Holds a reference to a std::string or C string. It can also be constructed
 // from an integer which is converted to a string.
 class StringHolder {
-public:
+ public:
   // Don't make the constructors explicit to make the StrCat usage convenient.
-  StringHolder(const string& s);
-  StringHolder(const char* s);
-  StringHolder(uint64 n);
+  StringHolder(const string& s);  // NOLINT(runtime/explicit)
+  StringHolder(const char* s);    // NOLINT(runtime/explicit)
+  StringHolder(uint64 n);         // NOLINT(runtime/explicit)
   ~StringHolder();
 
   const string* GetString() const {
@@ -95,7 +95,7 @@ public:
     return len_;
   }
 
-private:
+ private:
   const string converted_string_;  // Stores the string converted from integer.
   const string* const string_;
   const char* const cstring_;