diff --git a/demo-as-image.php b/demo-as-image.php
index 6c200b5..6f4e65e 100644
--- a/demo-as-image.php
+++ b/demo-as-image.php
@@ -12,7 +12,6 @@ for ($n = 0, $current = $offset + 0.5 * $scale; $n < 24; $n++) {
   $chartData[$n] = $current;
 }
 
-header('Content-type: image/svg+xml; charset=utf-8');
 $chart = new NeatCharts\LineChart($chartData, [
   'width'=>500,
   'height'=>400,
@@ -21,5 +20,8 @@ $chart = new NeatCharts\LineChart($chartData, [
   'smoothed'=>false,
   'fontSize'=>14
 ]);
+
+header('Content-type: image/svg+xml; charset=utf-8');
+echo '<?xml version="1.0" standalone="no"?>' . PHP_EOL;
 echo $chart->render();
 ?>
diff --git a/src/NeatCharts/LineChart.php b/src/NeatCharts/LineChart.php
index ec474a1..840c091 100644
--- a/src/NeatCharts/LineChart.php
+++ b/src/NeatCharts/LineChart.php
@@ -175,7 +175,7 @@ namespace NeatCharts {
         <stop offset="100%" stop-color="'.( $this->options['lineColor'] ).'" stop-opacity="1"></stop>
       </linearGradient>
     </defs>
-    <g class="SVGChart">
+    <g class="SVGChart">'.( $this->options['yAxisEnabled'] || $this->options['xAxisEnabled'] ? '
       <g class="chart__gridLines"
         shape-rendering="crispEdges"
         fill="none"
@@ -192,7 +192,7 @@ namespace NeatCharts {
         font-size="'.( $this->options['fontSize'] ).'px"
       >
         '.( $gridText ).'
-      </g>
+      </g>' : '').'
       <g class="chart__plotLine"
         fill="none"
         stroke-width="'.( $this->options['fontSize'] / 3 ).'"