diff --git a/src/BufferParams.cpp b/src/BufferParams.cpp
index 3906e5f665..cc73b016ca 100644
--- a/src/BufferParams.cpp
+++ b/src/BufferParams.cpp
@@ -2752,7 +2752,7 @@ DocumentClassConstPtr BufferParams::documentClassPtr() const
 }
 
 
-void BufferParams::setDocumentClass(DocumentClassConstPtr tc)
+void BufferParams::setDocumentClass(DocumentClassConstPtr const & tc)
 {
 	// evil, but this function is evil
 	doc_class_ = const_pointer_cast<DocumentClass>(tc);
diff --git a/src/BufferParams.h b/src/BufferParams.h
index 52abc6f229..73541c1b08 100644
--- a/src/BufferParams.h
+++ b/src/BufferParams.h
@@ -165,7 +165,7 @@ public:
 	/// This bypasses the baseClass and sets the textClass directly.
 	/// Should be called with care and would be better not being here,
 	/// but it seems to be needed by CutAndPaste::putClipboard().
-	void setDocumentClass(DocumentClassConstPtr);
+	void setDocumentClass(DocumentClassConstPtr const &);
 	/// List of modules in use
 	LayoutModuleList const & getModules() const { return layout_modules_; }
 	/// List of default modules the user has removed
diff --git a/src/BufferView.cpp b/src/BufferView.cpp
index 8f348d4169..41bc6b5c6a 100644
--- a/src/BufferView.cpp
+++ b/src/BufferView.cpp
@@ -1162,7 +1162,7 @@ void BufferView::makeDocumentClass()
 }
 
 
-void BufferView::updateDocumentClass(DocumentClassConstPtr olddc)
+void BufferView::updateDocumentClass(DocumentClassConstPtr const & olddc)
 {
 	StableDocIterator backcur(d->cursor_);
 	ErrorList & el = buffer_.errorList("Class Switch");
diff --git a/src/BufferView.h b/src/BufferView.h
index 24d3ce8950..0f673e38e6 100644
--- a/src/BufferView.h
+++ b/src/BufferView.h
@@ -456,7 +456,7 @@ private:
 	void updateHoveredInset() const;
 
 	///
-	void updateDocumentClass(DocumentClassConstPtr olddc);
+	void updateDocumentClass(DocumentClassConstPtr const & olddc);
 	///
 	int width_;
 	///
diff --git a/src/CutAndPaste.cpp b/src/CutAndPaste.cpp
index 26cfc9bec8..951c65a87f 100644
--- a/src/CutAndPaste.cpp
+++ b/src/CutAndPaste.cpp
@@ -600,7 +600,7 @@ PitPosPair eraseSelectionHelper(BufferParams const & params,
 }
 
 
-Buffer * copyToTempBuffer(ParagraphList const & paragraphs, DocumentClassConstPtr docclass)
+Buffer * copyToTempBuffer(ParagraphList const & paragraphs, DocumentClassConstPtr const & docclass)
 {
 	// This used to need to be static to avoid a memory leak. It no longer needs
 	// to be so, but the alternative is to construct a new one of these (with a
@@ -828,15 +828,15 @@ bool multipleCellsSelected(CursorData const & cur)
 }
 
 
-void switchBetweenClasses(DocumentClassConstPtr oldone,
-		DocumentClassConstPtr newone, InsetText & in) {
+void switchBetweenClasses(DocumentClassConstPtr const & oldone,
+		DocumentClassConstPtr const & newone, InsetText & in) {
 	ErrorList el = {};
 	switchBetweenClasses(oldone, newone, in, el);
 }
 
 
-void switchBetweenClasses(DocumentClassConstPtr oldone,
-		DocumentClassConstPtr newone, InsetText & in, ErrorList & errorlist)
+void switchBetweenClasses(DocumentClassConstPtr const & oldone,
+		DocumentClassConstPtr const & newone, InsetText & in, ErrorList & errorlist)
 {
 	errorlist.clear();
 
diff --git a/src/CutAndPaste.h b/src/CutAndPaste.h
index d7fec67c17..1b1c2f684d 100644
--- a/src/CutAndPaste.h
+++ b/src/CutAndPaste.h
@@ -138,11 +138,11 @@ void pasteParagraphList(Cursor & cur, ParagraphList const & parlist,
  *  It changes layouts and character styles. Errors are reported
  *  in the passed ErrorList.
  */
-void switchBetweenClasses(DocumentClassConstPtr oldone,
-            DocumentClassConstPtr newone, InsetText & in, ErrorList & el);
+void switchBetweenClasses(DocumentClassConstPtr const & oldone,
+            DocumentClassConstPtr const & newone, InsetText & in, ErrorList & el);
 /// Same but without error reporting.
-void switchBetweenClasses(DocumentClassConstPtr oldone,
-            DocumentClassConstPtr newone, InsetText & in);
+void switchBetweenClasses(DocumentClassConstPtr const & oldone,
+            DocumentClassConstPtr const & newone, InsetText & in);
 
 /// Get the current selection as a string. Does not change the selection.
 /// Does only work if the whole selection is in mathed.