diff --git a/.travis.yml b/.travis.yml
index 5739413..1c219c2 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,6 +5,11 @@ node_js:
   - '4'
   - '5'
   - '6'
+  - '8'
+  - '10'
+  - '11'
+  - '12'
+sudo: false
 addons:
   apt:
     sources:
diff --git a/core.cc b/core.cc
index 4b3f23c..a038b95 100644
--- a/core.cc
+++ b/core.cc
@@ -3,10 +3,9 @@
 #include <syslog.h>
 
 using v8::Function;
-using v8::FunctionTemplate;
-using v8::Handle;
+using v8::Int32;
+using v8::Isolate;
 using v8::Local;
-using v8::Null;
 using v8::Number;
 using v8::Object;
 using v8::String;
@@ -24,14 +23,15 @@ class Worker: public Nan::AsyncWorker {
         }
 
         void Execute() {
-            syslog(priority, "%s", message);
+            if(message)
+                syslog(priority, "%s", message);
         }
 
         void HandleOKCallback() {
             Nan::HandleScope scope;
 
             if(callback)
-                callback->Call(0, NULL);
+                callback->Call(0, NULL, async_resource);
         };
 
     private:
@@ -44,18 +44,26 @@ static char ident[1024];
 // wrap: void openlog(const char *ident, int option, int facility);
 NAN_METHOD(OpenLog) {
 
-    // openlog requires ident be statically allocated. Write doesn't guarantee
-    // NULL-termination, so preserve last byte as NULL.
-    info[0]->ToString()->WriteUtf8(ident, sizeof(ident)-1);
-    int option = info[1]->Int32Value();
-    int facility = info[2]->Int32Value();
+    const Nan::Utf8String arg0(info[0]);
+    Local<Int32> arg1 = Nan::To<Int32>(info[1]).ToLocalChecked();
+    Local<Int32> arg2 = Nan::To<Int32>(info[2]).ToLocalChecked();
+
+    // openlog() requires ident be statically allocated.
+    size_t length = arg0.length();
+    if(length) {
+      if(length > sizeof(ident)-1)
+        length = sizeof(ident)-1;
+      strncpy(ident, *arg0, length);
+    }
+    int option = arg1->Value();
+    int facility = arg2->Value();
 
     openlog(ident, option, facility);
 
     return;
 }
 
-static char* dupBuf(const Handle<Value>& arg) {
+static char* dupBuf(const Local<Value>& arg) {
     const char* mem = node::Buffer::Data(arg);
     size_t memsz = node::Buffer::Length(arg);
     char* s = new char[memsz + 1];
@@ -64,38 +72,36 @@ static char* dupBuf(const Handle<Value>& arg) {
     return s;
 }
 
-static char* dupStr(const Local<String>& m) {
-    if(m.IsEmpty())
-        return NULL;
-
-    // Exact calculation of UTF length involves double traversal. Avoid this
-    // because we know UTF8 expansion is < 4 bytes out per byte in.
-    char* s = new char[m->Length() * 4];
-    m->WriteUtf8(s);
+static char* dupStr(const Local<Value>& arg) {
+    const Nan::Utf8String str(arg);
+    const char* mem = *str;
+    size_t memsz = str.length();
+    char* s = new char[memsz + 1];
+    memcpy(s, mem, memsz);
+    s[memsz] = 0;
     return s;
 }
 
 // wrap: void syslog(int priority, const char *format, ...);
 NAN_METHOD(SysLog) {
 
-    int priority = info[0]->Int32Value();
+    Local<Int32> arg0 = Nan::To<Int32>(info[0]).ToLocalChecked();
+
+    int priority = arg0->Value();
     char* message = NULL;
     Nan::Callback *callback = NULL;
 
-    if (info[2]->IsFunction())
+    if(info[2]->IsFunction())
         callback = new Nan::Callback(info[2].As<Function>());
 
     if(node::Buffer::HasInstance(info[1])) {
         message = dupBuf(info[1]);
     } else {
-        message = dupStr(info[1]->ToString());
+        message = dupStr(info[1]);
     }
 
-    if (message) {
+    if(message || callback) {
         Nan::AsyncQueueWorker(new Worker(callback, priority, message));
-    } else if(callback) {
-        callback->Call(0, NULL);
-        delete callback;
     }
 
     return;
@@ -104,7 +110,8 @@ NAN_METHOD(SysLog) {
 // wrap: int setlogmask(int mask);
 NAN_METHOD(SetLogMask) {
 
-    int mask = info[0]->Int32Value();
+    Local<Int32> arg0 = Nan::To<Int32>(info[0]).ToLocalChecked();
+    int mask = arg0->Value();
     int last = setlogmask(mask);
 
     info.GetReturnValue().Set(Nan::New<Number>(last));
diff --git a/package.json b/package.json
index b350f33..78a2951 100644
--- a/package.json
+++ b/package.json
@@ -24,7 +24,7 @@
     "tap": "^1.3.2"
   },
   "dependencies": {
-    "nan": "^2.0.5"
+    "nan": "^2.13.2"
   },
   "tags": [
     "log",