diff --git a/firmware/baseband/dsp_demodulate.hpp b/firmware/baseband/dsp_demodulate.hpp
index 09149285..c5f871e1 100644
--- a/firmware/baseband/dsp_demodulate.hpp
+++ b/firmware/baseband/dsp_demodulate.hpp
@@ -55,9 +55,13 @@ public:
 		buffer_s16_t dst
 	);
 
+	void configure(const float sampling_rate, const float deviation_hz) {
+		k = static_cast<float>(32767.0f / (2.0 * pi * deviation_hz / sampling_rate));
+	}
+
 private:
 	complex16_t::rep_type z_;
-	const float k;
+	float k;
 };
 
 } /* namespace demodulate */
diff --git a/firmware/baseband/main.cpp b/firmware/baseband/main.cpp
index 7aedc677..75974d75 100755
--- a/firmware/baseband/main.cpp
+++ b/firmware/baseband/main.cpp
@@ -492,6 +492,7 @@ public:
 	}
 
 	void configure(const FSKConfiguration new_configuration) {
+		demod.configure(76800, 2 * new_configuration.symbol_rate);
 		clock_recovery.configure(new_configuration.symbol_rate, 76800);
 		access_code_correlator.configure(
 			new_configuration.access_code,