diff --git a/src/Buffer.cpp b/src/Buffer.cpp
index 398c6b5ab7..d3aa876e77 100644
--- a/src/Buffer.cpp
+++ b/src/Buffer.cpp
@@ -529,7 +529,7 @@ void Buffer::cloneWithChildren(BufferMap & bufmap, CloneList * clones) const
 
 	// The clone needs its own DocumentClass, since running updateBuffer() will
 	// modify it, and we would otherwise be sharing it with the original Buffer.
-	buffer_clone->params().makeDocumentClass();
+	buffer_clone->params().makeDocumentClass(true);
 	ErrorList el;
 	cap::switchBetweenClasses(
 			params().documentClassPtr(), buffer_clone->params().documentClassPtr(),
@@ -577,7 +577,7 @@ Buffer * Buffer::cloneBufferOnly() const {
 
 	// The clone needs its own DocumentClass, since running updateBuffer() will
 	// modify it, and we would otherwise be sharing it with the original Buffer.
-	buffer_clone->params().makeDocumentClass();
+	buffer_clone->params().makeDocumentClass(true);
 	ErrorList el;
 	cap::switchBetweenClasses(
 			params().documentClassPtr(), buffer_clone->params().documentClassPtr(),
diff --git a/src/BufferParams.cpp b/src/BufferParams.cpp
index 0604a99b0e..77769b2ab2 100644
--- a/src/BufferParams.cpp
+++ b/src/BufferParams.cpp
@@ -2101,7 +2101,7 @@ LayoutFileIndex const & BufferParams::baseClassID() const
 }
 
 
-void BufferParams::makeDocumentClass()
+void BufferParams::makeDocumentClass(bool const clone)
 {
 	if (!baseClass())
 		return;
@@ -2117,7 +2117,7 @@ void BufferParams::makeDocumentClass()
 	for (; it != en; ++it)
 		mods.push_back(*it);
 
-	doc_class_ = getDocumentClass(*baseClass(), mods);
+	doc_class_ = getDocumentClass(*baseClass(), mods, clone);
 
 	TextClass::ReturnValues success = TextClass::OK;
 	if (!forced_local_layout_.empty())
diff --git a/src/BufferParams.h b/src/BufferParams.h
index 9c558a6f5e..0825616cff 100644
--- a/src/BufferParams.h
+++ b/src/BufferParams.h
@@ -128,7 +128,7 @@ public:
 	/// on to class BufferView::updateDocumentClass(). The exception, of course,
 	/// is in GuiDocument, where we use a BufferParams simply to hold a copy of
 	/// the parameters from the active Buffer.
-	void makeDocumentClass();
+	void makeDocumentClass(bool const clone = false);
 	/// Returns the DocumentClass currently in use: the BaseClass as modified
 	/// by modules.
 	DocumentClass const & documentClass() const;
diff --git a/src/TextClass.cpp b/src/TextClass.cpp
index b77f31b336..391073d8ed 100644
--- a/src/TextClass.cpp
+++ b/src/TextClass.cpp
@@ -1489,7 +1489,8 @@ Layout TextClass::createBasicLayout(docstring const & name, bool unknown) const
 
 
 DocumentClassPtr getDocumentClass(
-		LayoutFile const & baseClass, LayoutModuleList const & modlist)
+		LayoutFile const & baseClass, LayoutModuleList const & modlist,
+		bool const clone)
 {
 	DocumentClassPtr doc_class =
 	    DocumentClassPtr(new DocumentClass(baseClass));
@@ -1504,10 +1505,11 @@ DocumentClassPtr getDocumentClass(
 						"this document but has not been found in the list of\n"
 						"available modules. If you recently installed it, you\n"
 						"probably need to reconfigure LyX.\n"), from_utf8(modName));
-			frontend::Alert::warning(_("Module not available"), msg);
+			if (!clone)
+				frontend::Alert::warning(_("Module not available"), msg);
 			continue;
 		}
-		if (!lm->isAvailable()) {
+		if (!lm->isAvailable() && !clone) {
 			docstring const prereqs = from_utf8(getStringFromVector(lm->prerequisites(), "\n\t"));
 			docstring const msg =
 				bformat(_("The module %1$s requires a package that is not\n"
diff --git a/src/TextClass.h b/src/TextClass.h
index 8e27fd85ef..fff3c2332f 100644
--- a/src/TextClass.h
+++ b/src/TextClass.h
@@ -491,7 +491,8 @@ private:
 	/// The only class that can create a DocumentClass is
 	/// DocumentClassBundle, which calls the protected constructor.
 	friend DocumentClassPtr
-		getDocumentClass(LayoutFile const &, LayoutModuleList const &);
+		getDocumentClass(LayoutFile const &, LayoutModuleList const &,
+				 bool const clone);
 	///
 	static InsetLayout plain_insetlayout_;
 };
@@ -502,7 +503,8 @@ private:
 /// in memory long after their associated Buffer is destroyed, mostly
 /// on the CutStack.
 DocumentClassPtr getDocumentClass(LayoutFile const & baseClass,
-			LayoutModuleList const & modlist);
+			LayoutModuleList const & modlist,
+			bool const clone = false);
 
 /// convert page sides option to text 1 or 2
 std::ostream & operator<<(std::ostream & os, PageSides p);
diff --git a/src/frontends/qt4/GuiDocument.cpp b/src/frontends/qt4/GuiDocument.cpp
index b80348a143..1ac9259586 100644
--- a/src/frontends/qt4/GuiDocument.cpp
+++ b/src/frontends/qt4/GuiDocument.cpp
@@ -2491,7 +2491,7 @@ void GuiDocument::updateDefaultFormat()
 	if (idx >= 0) {
 		string const classname = fromqstr(latexModule->classCO->getData(idx));
 		param_copy.setBaseClass(classname);
-		param_copy.makeDocumentClass();
+		param_copy.makeDocumentClass(true);
 	}
 	outputModule->defaultFormatCO->blockSignals(true);
 	outputModule->defaultFormatCO->clear();