diff --git a/appveyor.yml b/appveyor.yml
index 8bf753f..1e6ed81 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -5,9 +5,7 @@ environment:
   # Test against these versions of Node.js and io.js
   matrix:
     # node.js
-    - nodejs_version: "10"
-    - nodejs_version: "12"
-    - nodejs_version: "14"
+    - nodejs_version: "18"
 
 platform:
   - x86
@@ -52,4 +50,4 @@ deploy:
     auth_token: $(PREBUILD_GITHUB_TOKEN)
     on:
       appveyor_repo_tag: true
-      nodejs_version: "12"
+      nodejs_version: "18"
diff --git a/package.json b/package.json
index 56f79f5..04c8c60 100644
--- a/package.json
+++ b/package.json
@@ -2,7 +2,7 @@
   "name": "ref-napi",
   "description": "Turn Buffer instances into \"pointers\"",
   "engines": {
-    "node": ">= 10.0"
+    "node": ">= 18.0"
   },
   "keywords": [
     "native",
diff --git a/src/binding.cc b/src/binding.cc
index abd43ae..b1d429f 100644
--- a/src/binding.cc
+++ b/src/binding.cc
@@ -105,12 +105,12 @@ class InstanceData final : public RefNapi::Instance {
 
     auto it = pointer_to_orig_buffer.find(ptr);
     if (it != pointer_to_orig_buffer.end()) {
+      it->second.finalizer_count++;
       if (!it->second.ab.Value().IsEmpty()) {
         // Already have a valid entry, nothing to do.
         return;
       }
       it->second.ab.Reset(buf, 0);
-      it->second.finalizer_count++;
     } else {
       pointer_to_orig_buffer.emplace(ptr, ArrayBufferEntry {
         Reference<ArrayBuffer>::New(buf, 0),
@@ -140,8 +140,9 @@ class InstanceData final : public RefNapi::Instance {
     if (it != pointer_to_orig_buffer.end())
       ab = it->second.ab.Value();
 
-    if (ab.IsEmpty()) {
-      length = std::max<size_t>(length, kMaxLength);
+    if (ab.IsEmpty() || (ab.ByteLength() < length)) {
+      length = std::min<size_t>(length, kMaxLength);
+      length = std::max<size_t>(length,1);
       ab = Buffer<char>::New(env, ptr, length, [this](Env env, char* ptr) {
         UnregisterArrayBuffer(ptr);
       }).ArrayBuffer();
@@ -330,6 +331,8 @@ Value ReadPointer(const CallbackInfo& args) {
   int64_t size = args[2].ToNumber();
 
   char* val = *reinterpret_cast<char**>(ptr);
+  if(val != nullptr && size == 0) size = 1;
+
   return WrapPointer(env, val, size);
 }