diff --git a/binding.cc b/binding.cc
index d4cff53..fc5b312 100644
--- a/binding.cc
+++ b/binding.cc
@@ -285,6 +285,7 @@ static std::vector<std::string>* KeyArray (napi_env env, napi_value arr) {
           StringOrBufferLength(env, element) >= 0) {
         LD_STRING_OR_BUFFER_TO_COPY(env, element, to);
         result->emplace_back(toCh_, toSz_);
+        delete [] toCh_;
       }
     }
   }