diff --git a/src/node/ext/call.cc b/src/node/ext/call.cc
index 244546d3d785dfe919af05f7fc93ec4e30df78fb..5c311158542c43c45b971cb8e13497ea4027ef6a 100644
--- a/src/node/ext/call.cc
+++ b/src/node/ext/call.cc
@@ -574,6 +574,14 @@ void Call::CompleteBatch(bool is_final_op) {
 }
 
 NAN_METHOD(Call::New) {
+  /* Arguments:
+   * 0: Channel to make the call on
+   * 1: Method
+   * 2: Deadline
+   * 3: host
+   * 4: parent Call
+   * 5: propagation flags
+   */
   if (info.IsConstructCall()) {
     Call *call;
     if (info[0]->IsExternal()) {
@@ -618,25 +626,26 @@ NAN_METHOD(Call::New) {
       double deadline = Nan::To<double>(info[2]).FromJust();
       grpc_channel *wrapped_channel = channel->GetWrappedChannel();
       grpc_call *wrapped_call;
+      grpc_slice method = CreateSliceFromString(
+          Nan::To<String>(info[1]).ToLocalChecked());
       if (info[3]->IsString()) {
         grpc_slice *host = new grpc_slice;
         *host = CreateSliceFromString(
             Nan::To<String>(info[3]).ToLocalChecked());
         wrapped_call = grpc_channel_create_call(
             wrapped_channel, parent_call, propagate_flags,
-            GetCompletionQueue(), CreateSliceFromString(
-                Nan::To<String>(info[1]).ToLocalChecked()),
+            GetCompletionQueue(), method,
             host, MillisecondsToTimespec(deadline), NULL);
         delete host;
       } else if (info[3]->IsUndefined() || info[3]->IsNull()) {
         wrapped_call = grpc_channel_create_call(
             wrapped_channel, parent_call, propagate_flags,
-            GetCompletionQueue(), CreateSliceFromString(
-                Nan::To<String>(info[1]).ToLocalChecked()),
+            GetCompletionQueue(), method,
             NULL, MillisecondsToTimespec(deadline), NULL);
       } else {
         return Nan::ThrowTypeError("Call's fourth argument must be a string");
       }
+      grpc_slice_unref(method);
       call = new Call(wrapped_call);
       Nan::Set(info.This(), Nan::New("channel_").ToLocalChecked(),
                channel_object);
diff --git a/src/node/ext/node_grpc.cc b/src/node/ext/node_grpc.cc
index 95e273f8ac9fc31d173116f19fa50442af77beb6..122e5e63ee9d16c0eb9f0418e57761fdd29e5586 100644
--- a/src/node/ext/node_grpc.cc
+++ b/src/node/ext/node_grpc.cc
@@ -286,8 +286,10 @@ NAN_METHOD(MetadataKeyIsLegal) {
         "headerKeyIsLegal's argument must be a string");
   }
   Local<String> key = Nan::To<String>(info[0]).ToLocalChecked();
+  grpc_slice slice = CreateSliceFromString(key);
   info.GetReturnValue().Set(static_cast<bool>(
-      grpc_header_key_is_legal(CreateSliceFromString(key))));
+      grpc_header_key_is_legal(slice)));
+  grpc_slice_unref(slice);
 }
 
 NAN_METHOD(MetadataNonbinValueIsLegal) {
@@ -296,8 +298,10 @@ NAN_METHOD(MetadataNonbinValueIsLegal) {
         "metadataNonbinValueIsLegal's argument must be a string");
   }
   Local<String> value = Nan::To<String>(info[0]).ToLocalChecked();
+  grpc_slice slice = CreateSliceFromString(value);
   info.GetReturnValue().Set(static_cast<bool>(
-      grpc_header_nonbin_value_is_legal(CreateSliceFromString(value))));
+      grpc_header_nonbin_value_is_legal(slice)));
+  grpc_slice_unref(slice);
 }
 
 NAN_METHOD(MetadataKeyIsBinary) {
@@ -306,8 +310,10 @@ NAN_METHOD(MetadataKeyIsBinary) {
         "metadataKeyIsLegal's argument must be a string");
   }
   Local<String> key = Nan::To<String>(info[0]).ToLocalChecked();
+  grpc_slice slice = CreateSliceFromString(key);
   info.GetReturnValue().Set(static_cast<bool>(
-      grpc_is_binary_header(CreateSliceFromString(key))));
+      grpc_is_binary_header(slice)));
+  grpc_slice_unref(slice);
 }
 
 static grpc_ssl_roots_override_result get_ssl_roots_override(