diff --git a/FM.cpp b/FM.cpp
index 9928edd..d39bb46 100644
--- a/FM.cpp
+++ b/FM.cpp
@@ -71,6 +71,9 @@ m_filterStage3(32768, -65536, 32768, 32768, -64075, 31460),
 m_dsFilterStage1(  724,   1448,   724, 32768, -37895, 21352),//same design, separate state
 m_dsFilterStage2(32768,      0,-32768, 32768, -50339, 19052),
 m_dsFilterStage3(32768, -65536, 32768, 32768, -64075, 31460),
+m_usFilterStage1(  724,   1448,   724, 32768, -37895, 21352),//same design, separate state
+m_usFilterStage2(32768,      0,-32768, 32768, -50339, 19052),
+m_usFilterStage3(32768, -65536, 32768, 32768, -64075, 31460),
 m_blanking(),
 m_accessMode(1U),
 m_linkMode(false),
@@ -125,6 +128,7 @@ void CFM::repeaterSamples(bool cos, q15_t* samples, const uint16_t* rssi, uint8_
 
     q15_t currentExtSample;
     bool inputExt = m_inputExtRB.getSample(currentExtSample);//always consume the external input data so it does not overflow
+    currentExtSample = m_usFilterStage3.filter(m_usFilterStage2.filter(m_usFilterStage1.filter(currentExtSample)));
     inputExt = inputExt && m_extEnabled;
 
     switch (m_accessMode) {
@@ -270,6 +274,7 @@ void CFM::linkSamples(bool cos, q15_t* samples, uint8_t length)
     // few samples past that point
     q15_t currentExtSample = 0;
     bool inputExt = m_inputExtRB.getSample(currentExtSample);//always consume the external input data so it does not overflow
+    currentExtSample = m_usFilterStage3.filter(m_usFilterStage2.filter(m_usFilterStage1.filter(currentExtSample)));
     inputExt = inputExt && m_extEnabled;
 
     switch (m_accessMode) {
@@ -423,6 +428,9 @@ void CFM::reset()
   m_dsFilterStage1.reset();
   m_dsFilterStage2.reset();
   m_dsFilterStage3.reset();
+  m_usFilterStage1.reset();
+  m_usFilterStage2.reset();
+  m_usFilterStage3.reset();
   m_squelch.reset();
   
   m_needReverse = false;
diff --git a/FM.h b/FM.h
index 8d5f49b..29df859 100644
--- a/FM.h
+++ b/FM.h
@@ -83,6 +83,9 @@ private:
   CFMDirectFormI       m_dsFilterStage1; // anti-alias filter for the downsampler, own state
   CFMDirectFormI       m_dsFilterStage2;
   CFMDirectFormI       m_dsFilterStage3;
+  CFMDirectFormI       m_usFilterStage1; // reconstruction filter for the upsampler, own state
+  CFMDirectFormI       m_usFilterStage2;
+  CFMDirectFormI       m_usFilterStage3;
   CFMBlanking          m_blanking;
   uint8_t              m_accessMode;
   bool                 m_linkMode;