diff --git a/src/frontends/Clipboard.h b/src/frontends/Clipboard.h
index 42ecd6c1a5..67ce307e52 100644
--- a/src/frontends/Clipboard.h
+++ b/src/frontends/Clipboard.h
@@ -56,6 +56,8 @@ public:
 	/// (document contents, dialogs count as external here).
 	virtual bool isInternal() const = 0;
 	/// Is the clipboard empty?
+	/// \returns true if both the LyX and the plaintext versions of the
+	/// clipboard are empty.
 	virtual bool empty() const = 0;
 };
 
diff --git a/src/frontends/qt4/GuiClipboard.C b/src/frontends/qt4/GuiClipboard.C
index 03388b3c09..517676e800 100644
--- a/src/frontends/qt4/GuiClipboard.C
+++ b/src/frontends/qt4/GuiClipboard.C
@@ -116,7 +116,13 @@ bool GuiClipboard::isInternal() const
 
 bool GuiClipboard::empty() const
 {
-	return qApp->clipboard()->text(QClipboard::Clipboard).isEmpty();
+	// We need to check both the plaintext and the LyX version of the
+	// clipboard. The plaintext version is empty if the LyX version
+	// contains only one inset, and the LyX version is empry if the
+	// clipboard does not come from LyX.
+	if (!qApp->clipboard()->text(QClipboard::Clipboard).isEmpty())
+		return false;
+	return !hasLyXContents();
 }
 
 } // namespace frontend