diff --git a/src/node_os.cc b/src/node_os.cc
index 9e5530646a3708..fa38040e3af64a 100644
--- a/src/node_os.cc
+++ b/src/node_os.cc
@@ -22,6 +22,7 @@
 #include "node_internals.h"
 #include "string_bytes.h"
 
+#include <array>
 #include <errno.h>
 #include <string.h>
 
@@ -219,7 +220,7 @@ static void GetInterfaceAddresses(const FunctionCallbackInfo<Value>& args) {
   int count, i;
   char ip[INET6_ADDRSTRLEN];
   char netmask[INET6_ADDRSTRLEN];
-  char mac[18];
+  std::array<char, 18> mac;
   Local<Object> ret, o;
   Local<String> name, family;
   Local<Array> ifarr;
@@ -256,8 +257,8 @@ static void GetInterfaceAddresses(const FunctionCallbackInfo<Value>& args) {
       ret->Set(env->context(), name, ifarr).FromJust();
     }
 
-    snprintf(mac,
-             18,
+    snprintf(mac.data(),
+             mac.size(),
              "%02x:%02x:%02x:%02x:%02x:%02x",
              static_cast<unsigned char>(interfaces[i].phys_addr[0]),
              static_cast<unsigned char>(interfaces[i].phys_addr[1]),
diff --git a/src/node_url.cc b/src/node_url.cc
index a3f22f7c983e7d..6bf11897d8f2fa 100644
--- a/src/node_url.cc
+++ b/src/node_url.cc
@@ -786,10 +786,11 @@ inline bool ToASCII(const std::string& input, std::string* output) {
 
 void URLHost::ParseIPv6Host(const char* input, size_t length) {
   CHECK_EQ(type_, HostType::H_FAILED);
-  for (unsigned n = 0; n < 8; n++)
+  unsigned size = arraysize(value_.ipv6);
+  for (unsigned n = 0; n < size; n++)
     value_.ipv6[n] = 0;
   uint16_t* piece_pointer = &value_.ipv6[0];
-  uint16_t* const buffer_end = piece_pointer + 8;
+  uint16_t* const buffer_end = piece_pointer + size;
   uint16_t* compress_pointer = nullptr;
   const char* pointer = input;
   const char* end = pointer + length;
@@ -951,7 +952,7 @@ void URLHost::ParseIPv4Host(const char* input, size_t length, bool* is_ipv4) {
     const char ch = pointer < end ? pointer[0] : kEOL;
     const int remaining = end - pointer - 1;
     if (ch == '.' || ch == kEOL) {
-      if (++parts > 4)
+      if (++parts > static_cast<int>(arraysize(numbers)))
         return;
       if (pointer == mark)
         return;
diff --git a/src/util.h b/src/util.h
index 086e33933e6b5a..9dd39fe1860b8e 100644
--- a/src/util.h
+++ b/src/util.h
@@ -37,6 +37,7 @@
 #include <functional>  // std::function
 #include <set>
 #include <string>
+#include <array>
 #include <unordered_map>
 
 namespace node {
@@ -223,6 +224,14 @@ inline v8::Local<v8::String> FIXED_ONE_BYTE_STRING(
   return OneByteString(isolate, data, N - 1);
 }
 
+template <std::size_t N>
+inline v8::Local<v8::String> FIXED_ONE_BYTE_STRING(
+    v8::Isolate* isolate,
+    const std::array<char, N>& arr) {
+  return OneByteString(isolate, arr.data(), N - 1);
+}
+
+
 
 // Swaps bytes in place. nbytes is the number of bytes to swap and must be a
 // multiple of the word size (checked by function).