diff --git a/classes/Visualizer/Source.php b/classes/Visualizer/Source.php
index 03e7c99ad..7b3d6b597 100644
--- a/classes/Visualizer/Source.php
+++ b/classes/Visualizer/Source.php
@@ -429,7 +429,7 @@ private function _fetchSeriesFromEditableTable() {
 			foreach ( $headers as $header ) {
 				if ( ! empty( $types[ $header ] ) ) {
 					$this->_series[] = array(
-						'label' => esc_html( wp_strip_all_tags( $header ) ),
+						'label' => sanitize_text_field( wp_strip_all_tags( $header ) ),
 						'type'  => $types[ $header ],
 					);
 				}
diff --git a/classes/Visualizer/Source/Csv.php b/classes/Visualizer/Source/Csv.php
index 461fd8dbf..796658646 100644
--- a/classes/Visualizer/Source/Csv.php
+++ b/classes/Visualizer/Source/Csv.php
@@ -97,7 +97,7 @@ private function _fetchSeries( &$handle ) {
 			$labels[ $i ] = $this->toUTF8( $labels[ $i ] );
 
 			$this->_series[] = array(
-				'label' => esc_html( wp_strip_all_tags( $labels[ $i ] ) ),
+				'label' => sanitize_text_field( wp_strip_all_tags( $labels[ $i ] ) ),
 				'type'  => isset( $types[ $i ] ) ? $types[ $i ] : $default_type,
 			);
 		}