diff --git a/README.md b/README.md
index 640b5f2c..6d39ecee 100644
--- a/README.md
+++ b/README.md
@@ -288,7 +288,6 @@ If the library is configured for US915 operation, we make the following changes:
 
 - Add the APIs `LMIC_enableChannel()`,
 `LMIC_enableSubBand()`, `LMIC_disableSubBand()`, and `LMIC_selectSubBand()`.
-- Add the constants `MAX_XCHANNELS`.
 - Add a number of additional `DR_...` symbols.
 
 ### Selecting the target radio transceiver
diff --git a/src/lmic/lmic.h b/src/lmic/lmic.h
index 471f1f96..8fa7d760 100644
--- a/src/lmic/lmic.h
+++ b/src/lmic/lmic.h
@@ -172,10 +172,8 @@ struct lmic_saved_adr_state_s {
 
 #elif CFG_LMIC_US_like  // US915 spectrum =================================================
 
-enum { MAX_XCHANNELS = 2 };      // extra channels in RAM, channels 0-71 are immutable
-
 struct lmic_saved_adr_state_s {
-    u2_t        channelMap[(72+MAX_XCHANNELS+15)/16];  // enabled bits
+    u2_t        channelMap[(72+15)/16];  // enabled bits
     u2_t        activeChannels125khz;
     u2_t        activeChannels500khz;
 };
@@ -532,9 +530,7 @@ struct lmic_t {
     u2_t        channelDrMap[MAX_CHANNELS];
     u2_t        channelMap;
 #elif CFG_LMIC_US_like
-    u4_t        xchFreq[MAX_XCHANNELS];    // extra channel frequencies (if device is behind a repeater)
-    u2_t        xchDrMap[MAX_XCHANNELS];   // extra channel datarate ranges  ---XXX: ditto
-    u2_t        channelMap[(72+MAX_XCHANNELS+15)/16];  // enabled bits
+    u2_t        channelMap[(72+15)/16];  // enabled bits
     u2_t        activeChannels125khz;
     u2_t        activeChannels500khz;
 #endif
diff --git a/src/lmic/lmic_us915.c b/src/lmic/lmic_us915.c
index 0d84ac13..352d687e 100644
--- a/src/lmic/lmic_us915.c
+++ b/src/lmic/lmic_us915.c
@@ -100,20 +100,17 @@ u4_t LMICus915_convFreq(xref2cu1_t ptr) {
 }
 
 bit_t LMIC_setupChannel(u1_t chidx, u4_t freq, u2_t drmap, s1_t band) {
+        LMIC_API_PARAMETER(chidx);
+        LMIC_API_PARAMETER(freq);
+        LMIC_API_PARAMETER(drmap);
         LMIC_API_PARAMETER(band);
 
-        if (chidx < 72 || chidx >= 72 + MAX_XCHANNELS)
-                return 0; // channels 0..71 are hardwired
-        LMIC.xchFreq[chidx - 72] = freq;
-        // TODO(tmm@mcci.com): don't use US SF directly, use something from the LMIC context or a static const
-        LMIC.xchDrMap[chidx - 72] = drmap == 0 ? DR_RANGE_MAP(US915_DR_SF10, US915_DR_SF8C) : drmap;
-        LMIC.channelMap[chidx >> 4] |= (1 << (chidx & 0xF));
-        return 1;
+        return 0; // channels 0..71 are hardwired
 }
 
 bit_t LMIC_disableChannel(u1_t channel) {
         bit_t result = 0;
-        if (channel < 72 + MAX_XCHANNELS) {
+        if (channel < 72) {
                 if (ENABLED_CHANNEL(channel)) {
                         result = 1;
                         if (IS_CHANNEL_125khz(channel))
@@ -128,7 +125,7 @@ bit_t LMIC_disableChannel(u1_t channel) {
 
 bit_t LMIC_enableChannel(u1_t channel) {
         bit_t result = 0;
-        if (channel < 72 + MAX_XCHANNELS) {
+        if (channel < 72) {
                 if (!ENABLED_CHANNEL(channel)) {
                         result = 1;
                         if (IS_CHANNEL_125khz(channel))
@@ -197,13 +194,7 @@ void LMICus915_updateTx(ostime_t txbeg) {
         } else {
                 // at 500kHz bandwidth, we're allowed more power.
                 LMIC.txpow = 26;
-                if (chnl < 64 + 8) {
-                        LMIC.freq = US915_500kHz_UPFBASE + (chnl - 64)*US915_500kHz_UPFSTEP;
-                }
-                else {
-                        ASSERT(chnl < 64 + 8 + MAX_XCHANNELS);
-                        LMIC.freq = LMIC.xchFreq[chnl - 72];
-                }
+                LMIC.freq = US915_500kHz_UPFBASE + (chnl - 64)*US915_500kHz_UPFSTEP;
         }
 
         // Update global duty cycle stats