diff --git a/lightningd/pay.c b/lightningd/pay.c
index 515230f0d..3af9afd99 100644
--- a/lightningd/pay.c
+++ b/lightningd/pay.c
@@ -129,9 +129,6 @@ void json_add_payment_fields(struct json_stream *response,
 	if (amount_msat_greater(t->msatoshi, AMOUNT_MSAT(0)))
 		json_add_amount_msat_compat(response, t->msatoshi, "msatoshi",
 					    "amount_msat");
-	else if (deprecated_apis)
-		json_add_null(response, "amount_msat");
-
 
 	json_add_amount_msat_compat(response, t->msatoshi_sent,
 				    "msatoshi_sent", "amount_sent_msat");
diff --git a/plugins/pay.c b/plugins/pay.c
index 2a79f5ee5..c32d332e3 100644
--- a/plugins/pay.c
+++ b/plugins/pay.c
@@ -1722,8 +1722,7 @@ static void add_amount_sent(struct plugin *p,
 
 	/* If this is an unannotated partial payment we drop out estimate for
 	 * all parts. */
-	/* FIXME: with deprecated_apis, amount_msat can be 'null' */
-	if (msattok == NULL || !json_to_msat(buf, msattok, &recv)) {
+	if (msattok == NULL) {
 		mpp->amount = tal_free(mpp->amount);
 		return;
 	}
@@ -1734,6 +1733,11 @@ static void add_amount_sent(struct plugin *p,
 	if (mpp->amount == NULL)
 		return;
 
+	if (!json_to_msat(buf, msattok, &recv))
+		plugin_err(p, "Cannot convert amount_sat %.*s",
+			   json_tok_full_len(msattok),
+			   json_tok_full(buf, msattok));
+
 	if (!amount_msat_add(mpp->amount, *mpp->amount, recv))
 		plugin_log(p, LOG_BROKEN,
 			   "Cannot add amount_msat for %s: %s + %s",