diff --git a/libs/ardour/ardour/dsp_filter.h b/libs/ardour/ardour/dsp_filter.h
index ed31bb6012..c79732a018 100644
--- a/libs/ardour/ardour/dsp_filter.h
+++ b/libs/ardour/ardour/dsp_filter.h
@@ -248,6 +248,9 @@ namespace ARDOUR { namespace DSP {
 			/** setup filter, set coefficients directly */
 			void configure (double a1, double a2, double b0, double b1, double b2);
 
+			/* copy coefficients from other instance, retain state */
+			void configure (Biquad const&);
+
 			/** filter transfer function (filter response for spectrum visualization)
 			 * @param freq frequency
 			 * @return gain at given frequency in dB (clamped to -120..+120)
diff --git a/libs/ardour/dsp_filter.cc b/libs/ardour/dsp_filter.cc
index 8ff5a35033..861c61110c 100644
--- a/libs/ardour/dsp_filter.cc
+++ b/libs/ardour/dsp_filter.cc
@@ -196,6 +196,16 @@ Biquad::configure (double a1, double a2, double b0, double b1, double b2)
 	_b2 = b2;
 }
 
+void
+Biquad::configure (Biquad const& other)
+{
+	_a1 = other._a1;
+	_a2 = other._a2;
+	_b0 = other._b0;
+	_b1 = other._b1;
+	_b2 = other._b2;
+}
+
 void
 Biquad::compute (Type type, double freq, double Q, double gain)
 {
diff --git a/libs/ardour/luabindings.cc b/libs/ardour/luabindings.cc
index c757558216..798909a0e0 100644
--- a/libs/ardour/luabindings.cc
+++ b/libs/ardour/luabindings.cc
@@ -2790,7 +2790,7 @@ LuaBindings::common (lua_State* L)
 		.addConstructor <void (*) (double)> ()
 		.addFunction ("run", &DSP::Biquad::run)
 		.addFunction ("compute", &DSP::Biquad::compute)
-		.addFunction ("configure", &DSP::Biquad::configure)
+		.addFunction ("configure", (void (DSP::Biquad::*) (DSP::Biquad const&))&DSP::Biquad::configure)
 		.addFunction ("reset", &DSP::Biquad::reset)
 		.addFunction ("dB_at_freq", &DSP::Biquad::dB_at_freq)
 		.endClass ()