diff --git a/documentation/ref-manual/ref-variables.xml b/documentation/ref-manual/ref-variables.xml
index bb6d970e32..42a6d3ddc4 100644
--- a/documentation/ref-manual/ref-variables.xml
+++ b/documentation/ref-manual/ref-variables.xml
@@ -2344,6 +2344,16 @@
             </glossdef>
         </glossentry>
 
+        <glossentry id='var-EXTRA_IMAGECMD'><glossterm>EXTRA_IMAGECMD</glossterm>
+            <glossdef>
+                <para>
+                    Specifies additional options for the image
+                    creation command that has been specified in
+                    <link linkend='var-IMAGE_CMD'><filename>IMAGE_CMD</filename></link>.
+                </para>
+            </glossdef>
+        </glossentry>
+
         <glossentry id='var-EXTRA_IMAGEDEPENDS'><glossterm>EXTRA_IMAGEDEPENDS</glossterm>
             <glossdef>
                 <para>A list of recipes to build that do not provide packages