diff --git a/qtism/data/content/xhtml/html5/Figcaption.php b/qtism/data/content/xhtml/html5/Figcaption.php
index cfcd2b966..910c30f71 100644
--- a/qtism/data/content/xhtml/html5/Figcaption.php
+++ b/qtism/data/content/xhtml/html5/Figcaption.php
@@ -22,9 +22,7 @@
 
 namespace qtism\data\content\xhtml\html5;
 
-use qtism\data\content\FlowStatic;
-
-class Figcaption extends Html5LayoutElement implements FlowStatic
+class Figcaption extends Html5LayoutElement
 {
     public const QTI_CLASS_NAME_FIGCAPTION = 'figcaption';
 
diff --git a/qtism/data/content/xhtml/html5/Figure.php b/qtism/data/content/xhtml/html5/Figure.php
index 221923010..be7dea05e 100644
--- a/qtism/data/content/xhtml/html5/Figure.php
+++ b/qtism/data/content/xhtml/html5/Figure.php
@@ -20,12 +20,13 @@
 
 namespace qtism\data\content\xhtml\html5;
 
-use qtism\data\content\FlowStatic;
+use qtism\data\content\Inline;
+use qtism\data\content\TextOrVariable;
 
 /**
  * The XHTML figure class.
  */
-class Figure extends Html5LayoutElement implements FlowStatic
+class Figure extends Html5LayoutElement implements Inline, TextOrVariable
 {
     public const QTI_CLASS_NAME_FIGURE = 'figure';
 
diff --git a/qtism/data/content/xhtml/html5/Rb.php b/qtism/data/content/xhtml/html5/Rb.php
index 72a50a8f6..3a08d2ff0 100644
--- a/qtism/data/content/xhtml/html5/Rb.php
+++ b/qtism/data/content/xhtml/html5/Rb.php
@@ -22,9 +22,7 @@
 
 namespace qtism\data\content\xhtml\html5;
 
-use qtism\data\content\FlowStatic;
-
-class Rb extends Html5LayoutElement implements FlowStatic
+class Rb extends Html5LayoutElement
 {
     public const QTI_CLASS_NAME = 'rb';
 
diff --git a/qtism/data/content/xhtml/html5/Rp.php b/qtism/data/content/xhtml/html5/Rp.php
index f284969da..6f0e4652d 100644
--- a/qtism/data/content/xhtml/html5/Rp.php
+++ b/qtism/data/content/xhtml/html5/Rp.php
@@ -22,9 +22,7 @@
 
 namespace qtism\data\content\xhtml\html5;
 
-use qtism\data\content\FlowStatic;
-
-class Rp extends Html5LayoutElement implements FlowStatic
+class Rp extends Html5LayoutElement
 {
     public const QTI_CLASS_NAME = 'rp';
 
diff --git a/qtism/data/content/xhtml/html5/Rt.php b/qtism/data/content/xhtml/html5/Rt.php
index c255adb24..34737dee9 100644
--- a/qtism/data/content/xhtml/html5/Rt.php
+++ b/qtism/data/content/xhtml/html5/Rt.php
@@ -22,9 +22,7 @@
 
 namespace qtism\data\content\xhtml\html5;
 
-use qtism\data\content\FlowStatic;
-
-class Rt extends Html5LayoutElement implements FlowStatic
+class Rt extends Html5LayoutElement
 {
     public const QTI_CLASS_NAME = 'rt';
 
diff --git a/qtism/data/content/xhtml/html5/Ruby.php b/qtism/data/content/xhtml/html5/Ruby.php
index 473530377..a36f913ec 100644
--- a/qtism/data/content/xhtml/html5/Ruby.php
+++ b/qtism/data/content/xhtml/html5/Ruby.php
@@ -22,9 +22,11 @@
 
 namespace qtism\data\content\xhtml\html5;
 
-use qtism\data\content\FlowStatic;
+use qtism\data\content\Inline;
+use qtism\data\content\InlineStatic;
+use qtism\data\content\TextOrVariable;
 
-class Ruby extends Html5LayoutElement implements FlowStatic
+class Ruby extends Html5LayoutElement implements Inline, TextOrVariable, InlineStatic
 {
     public const QTI_CLASS_NAME = 'ruby';
 
@@ -33,3 +35,5 @@ public function getQtiClassName()
         return self::QTI_CLASS_NAME;
     }
 }
+
+
diff --git a/qtism/data/storage/xml/marshalling/GapChoiceMarshaller.php b/qtism/data/storage/xml/marshalling/GapChoiceMarshaller.php
index f14ea3f25..47b6e64af 100644
--- a/qtism/data/storage/xml/marshalling/GapChoiceMarshaller.php
+++ b/qtism/data/storage/xml/marshalling/GapChoiceMarshaller.php
@@ -26,6 +26,7 @@
 use DOMElement;
 use InvalidArgumentException;
 use qtism\data\content\FlowStaticCollection;
+use qtism\data\content\xhtml\html5\Ruby;
 use qtism\data\QtiComponent;
 use qtism\data\QtiComponentCollection;
 use qtism\data\ShowHide;
@@ -65,6 +66,7 @@ class GapChoiceMarshaller extends ContentMarshaller
         'textRun',
         'tt',
         'var',
+        Ruby::QTI_CLASS_NAME
     ];
 
     /**