diff --git a/src/insets/Inset.h b/src/insets/Inset.h
index da160e447c..6f43cee5b4 100644
--- a/src/insets/Inset.h
+++ b/src/insets/Inset.h
@@ -449,7 +449,7 @@ public:
 	 *  Most insets have no interest in this capability, so the method
 	 *  defaults to empty.
 	 */
-	virtual void addPreview(DocIterator const & insetPos,
+	virtual void addPreview(DocIterator const &,
 		graphics::PreviewLoader &) const {}
 
 	/** Classifies the unicode characters appearing in a math inset