diff --git a/src/mt63/mt63.cxx b/src/mt63/mt63.cxx
index eca10a4a..6185f040 100644
--- a/src/mt63/mt63.cxx
+++ b/src/mt63/mt63.cxx
@@ -117,6 +117,8 @@ int mt63::rx_process(const double *buf, int len)
 	unsigned int c;
 	int i;
 
+	if (get_freq() != (500.0 + bandwidth / 2.0)) 	set_freq(500.0 + bandwidth / 2.0);
+
 	if (Interleave != progdefaults.mt63_interleave) {
 		Interleave = progdefaults.mt63_interleave;
 		restart();