diff --git a/onchaind/onchaind.c b/onchaind/onchaind.c
index fe88ffb10c37..ccdbdf836241 100644
--- a/onchaind/onchaind.c
+++ b/onchaind/onchaind.c
@@ -143,6 +143,55 @@ static bool wally_tx_output_scripteq(const struct wally_tx_output *out,
 	return memeq(out->script, out->script_len, script, tal_bytelen(script));
 }
 
+/* The feerate for the HTLC txs (which we grind) are the same as the
+ * feerate for the main tx.  However, there may be dust HTLCs which
+ * were added to the fee, so we can only estimate a maximum feerate */
+static void trim_maximum_feerate(struct amount_sat funding,
+				 const struct tx_parts *commitment)
+{
+	size_t weight;
+	struct amount_sat fee = funding;
+
+	/* FIXME: This doesn't work for elements? */
+	if (chainparams->is_elements)
+		return;
+
+	weight = bitcoin_tx_core_weight(tal_count(commitment->inputs),
+					tal_count(commitment->outputs));
+
+	/* BOLT #3:
+	 * ## Commitment Transaction
+	 *...
+	 *   * `txin[0]` script bytes: 0
+	 *   * `txin[0]` witness: `0 <signature_for_pubkey1> <signature_for_pubkey2>`
+	 */
+	/* Account for witness (1 byte count + 1 empty + sig + sig) */
+	assert(tal_count(commitment->inputs) == 1);
+	weight += bitcoin_tx_input_weight(false, 1 + 1 + 2 * bitcoin_tx_input_sig_weight());
+
+	for (size_t i = 0; i < tal_count(commitment->outputs); i++) {
+		struct amount_asset amt;
+		weight += bitcoin_tx_output_weight(commitment->outputs[i]
+						   ->script_len);
+
+		amt = wally_tx_output_get_amount(commitment->outputs[i]);
+		if (!amount_asset_is_main(&amt))
+			continue;
+		if (!amount_sat_sub(&fee, fee, amount_asset_to_sat(&amt))) {
+			status_failed(STATUS_FAIL_INTERNAL_ERROR,
+				      "Unable to subtract fee");
+		}
+	}
+
+	status_debug("reducing max_possible_feerate from %u...",
+		     max_possible_feerate);
+	/* This is naive, but simple. */
+	while (amount_sat_greater(amount_tx_fee(max_possible_feerate, weight),
+				  fee))
+		max_possible_feerate--;
+	status_debug("... to %u", max_possible_feerate);
+}
+
 static void send_coin_mvt(struct chain_coin_mvt *mvt TAKES)
 {
 	wire_sync_write(REQ_FD,
@@ -3767,6 +3816,8 @@ int main(int argc, char *argv[])
 		     type_to_string(tmpctx, struct pubkey,
 				    &old_remote_per_commit_point));
 
+	trim_maximum_feerate(funding, tx);
+
 	/* BOLT #5:
 	 *
 	 * There are three ways a channel can end: