diff --git a/lib/ads.js b/lib/ads.js
index e4b4896..07a9440 100755
--- a/lib/ads.js
+++ b/lib/ads.js
@@ -315,7 +315,7 @@ var multiRead = function (handles, cb) {
         var index = 0
         handles.forEach(function(handle) {
           if (!handle.err){
-            buf.writeUInt32LE(handle.indexGroup || ADSIGRP.RW_SYMVAL_BYHANDLE,index)
+            buf.writeUInt32LE(Number.isNaN(handle.indexGroup) ? ADSIGRP.RW_SYMVAL_BYHANDLE : handle.indexGroup,index)
             buf.writeUInt32LE(handle.indexOffset || handle.symhandle,index+4)
             buf.writeUInt32LE(handle.totalByteLength,index+8)
             index+=12
@@ -381,7 +381,7 @@ var multiWrite = function (handles, cb) {
         var valindex = 12*countwrites
         handles.forEach(function(handle) {
           if (!handle.err){
-            buf.writeUInt32LE(handle.indexGroup || ADSIGRP.RW_SYMVAL_BYHANDLE,0)
+            buf.writeUInt32LE(Number.isNaN(handle.indexGroup) ? ADSIGRP.RW_SYMVAL_BYHANDLE : handle.indexGroup,0)
             buf.writeUInt32LE(handle.indexOffset || handle.symhandle,4)
             buf.writeUInt32LE(handle.totalByteLength,8)
             index+=12
@@ -497,7 +497,7 @@ var read = function (handle, cb) {
   getHandle.call(ads, handle, function (err, handle) {
     if (!err) {
       var commandOptions = {
-        indexGroup: handle.indexGroup || ADSIGRP.RW_SYMVAL_BYHANDLE,
+        indexGroup: Number.isNaN(handle.indexGroup) ? ADSIGRP.RW_SYMVAL_BYHANDLE : handle.indexGroup,
         indexOffset: handle.indexOffset || handle.symhandle,
         bytelength: handle.totalByteLength,
         symname: handle.symname
@@ -519,7 +519,7 @@ var write = function (handle, cb) {
     if (!err) {
       getBytesFromHandle(handle)
       var commandOptions = {
-        indexGroup: handle.indexGroup || ADSIGRP.RW_SYMVAL_BYHANDLE,
+        indexGroup: Number.isNaN(handle.indexGroup) ? ADSIGRP.RW_SYMVAL_BYHANDLE : handle.indexGroup,
         indexOffset: handle.indexOffset || handle.symhandle,
         bytelength: handle.totalByteLength,
         bytes: handle.bytes,
@@ -540,7 +540,7 @@ var notify = function (handle, cb) {
   getHandle.call(ads, handle, function (err, handle) {
     if (!err) {
       var commandOptions = {
-        indexGroup: handle.indexGroup || ADSIGRP.RW_SYMVAL_BYHANDLE,
+        indexGroup: Number.isNaN(handle.indexGroup) ? ADSIGRP.RW_SYMVAL_BYHANDLE : handle.indexGroup,
         indexOffset: handle.indexOffset || handle.symhandle,
         bytelength: handle.totalByteLength,
         transmissionMode: handle.transmissionMode,