diff --git a/libs/ardour/ardour/buffer.h b/libs/ardour/ardour/buffer.h
index 4570a7a663..0d0f5d3758 100644
--- a/libs/ardour/ardour/buffer.h
+++ b/libs/ardour/ardour/buffer.h
@@ -61,7 +61,6 @@ public:
 	DataType type() const { return _type; }
 
 	bool silent() const { return _silent; }
-	void set_is_silent(bool yn) { _silent = yn; }
 
 	/** Reallocate the buffer used internally to handle at least @a size_t units of data.
 	 *
diff --git a/libs/ardour/ardour/buffer_set.h b/libs/ardour/ardour/buffer_set.h
index 26d47682af..5f8553218b 100644
--- a/libs/ardour/ardour/buffer_set.h
+++ b/libs/ardour/ardour/buffer_set.h
@@ -86,7 +86,6 @@ public:
 	const ChanCount& count() const { return _count; }
 	ChanCount&       count()       { return _count; }
 
-	void set_is_silent(bool yn);
 	void silence (framecnt_t nframes, framecnt_t offset);
 	bool is_mirror() const { return _is_mirror; }
 
diff --git a/libs/ardour/buffer_set.cc b/libs/ardour/buffer_set.cc
index 227d7a1e95..9db99d20ce 100644
--- a/libs/ardour/buffer_set.cc
+++ b/libs/ardour/buffer_set.cc
@@ -468,16 +468,5 @@ BufferSet::silence (framecnt_t nframes, framecnt_t offset)
 	}
 }
 
-void
-BufferSet::set_is_silent (bool yn)
-{
-	for (std::vector<BufferVec>::iterator i = _buffers.begin(); i != _buffers.end(); ++i) {
-		for (BufferVec::iterator b = i->begin(); b != i->end(); ++b) {
-			(*b)->set_is_silent (yn);
-		}
-	}
-
-}
-
 } // namespace ARDOUR