diff --git a/wp-admin/includes/ajax-actions.php b/wp-admin/includes/ajax-actions.php
index 06d47af870..8a7b6a15a2 100644
--- a/wp-admin/includes/ajax-actions.php
+++ b/wp-admin/includes/ajax-actions.php
@@ -2158,7 +2158,7 @@ function wp_ajax_revisions_data() {
 			$left_content = apply_filters( "_wp_post_revision_field_$field", $left_revision->$field, $field, $left_revision, 'left' );
 			$right_content = apply_filters( "_wp_post_revision_field_$field", $right_revision->$field, $field, $right_revision, 'right' );
 
-			add_filter( "_wp_post_revision_field_$field", 'wp_kses_post' );
+			add_filter( "_wp_post_revision_field_$field", 'htmlspecialchars' );
 
 			$args = array();
 
diff --git a/wp-includes/wp-diff.php b/wp-includes/wp-diff.php
index be6187f697..62f4162fa3 100644
--- a/wp-includes/wp-diff.php
+++ b/wp-includes/wp-diff.php
@@ -154,7 +154,7 @@ class WP_Text_Diff_Renderer_Table extends Text_Diff_Renderer {
 		$r = '';
 		foreach ($lines as $line) {
 			if ( $encode )
-				$line = wp_kses_post( $line );
+				$line = htmlspecialchars( $line );
 			if ( $this->_show_split_view ) {
 				$r .= '<tr>' . $this->emptyLine() . $this->emptyLine() . $this->addedLine( $line ) . "</tr>\n";
 			} else {
@@ -176,7 +176,7 @@ class WP_Text_Diff_Renderer_Table extends Text_Diff_Renderer {
 		$r = '';
 		foreach ($lines as $line) {
 			if ( $encode )
-				$line = wp_kses_post( $line );
+				$line = htmlspecialchars( $line );
 			if ( $this->_show_split_view ) {
 				$r .= '<tr>' . $this->deletedLine( $line ) . $this->emptyLine() . $this->emptyLine() . "</tr>\n";
 			} else {
@@ -199,7 +199,7 @@ class WP_Text_Diff_Renderer_Table extends Text_Diff_Renderer {
 		$r = '';
 		foreach ($lines as $line) {
 			if ( $encode )
-				$line = wp_kses_post( $line );
+				$line = htmlspecialchars( $line );
 			if (  $this->_show_split_view ) {
 				$r .= '<tr>' . $this->contextLine( $line ) . $this->emptyLine() . $this->contextLine( $line )  . "</tr>\n";
 			} else {