diff --git a/improved_text_trim.module b/improved_text_trim.module
index 76d818b..d033593 100644
--- a/improved_text_trim.module
+++ b/improved_text_trim.module
@@ -122,6 +122,9 @@ function improved_text_trim_summary($text, $size = NULL) {
     // until $size limit is reached.
     _improved_text_trim_summarize($body_node, $size, $summary_doc, $summary_doc);
 
+    // Makes sure that iframes won't be converted to <iframe /> form.
+    _improved_text_trim_ensure_tag($summary_doc, 'iframe');
+
     // Convert the summary document back to XHTML.
     $output = filter_dom_serialize($summary_doc);
   }
@@ -137,6 +140,30 @@ function improved_text_trim_summary($text, $size = NULL) {
 }
 
 /**
+ * Ensures that a certain tag keeps it open-close pair form.
+ *
+ * Example:
+ * <tag></tag> won't get sqashed to <tag />
+ *
+ * There are certain HTML tags which behaves badly in their short form.
+ * A good example is the <iframe> tag.
+ *
+ * @param DOMDocument $document
+ *   The source DOMDocument
+ * @param string $tagname
+ *   The name of the tag which should be preserved.
+ */
+function _improved_text_trim_ensure_tag($document, $tagname) {
+  $xpath = new DOMXPath($document);
+  $tags = $xpath->query("//{$tagname}");
+  foreach ($tags as $tag) {
+    if (!strlen($tag->textContent)) {
+      $tag->appendChild(new DOMText(' '));
+    }
+  }
+}
+
+/**
  * Helper function for improved_text_trim_summary().
  *
  * Recursively copies elements from $body to $summary, subtracting the length