diff --git a/common/amount.c b/common/amount.c
index fa1870700..e17a68044 100644
--- a/common/amount.c
+++ b/common/amount.c
@@ -18,6 +18,16 @@ bool amount_sat_to_msat(struct amount_msat *msat,
 	return true;
 }
 
+bool amount_msat_to_sat(struct amount_sat *sat,
+			struct amount_msat msat)
+{
+	if (msat.millisatoshis % MSAT_PER_SAT)
+		return false;
+	sat->satoshis = msat.millisatoshis / MSAT_PER_SAT;
+	return true;
+}
+
+
 /* You can always truncate millisatoshis->satoshis. */
 struct amount_sat amount_msat_to_sat_round_down(struct amount_msat msat)
 {
diff --git a/common/amount.h b/common/amount.h
index b7277d7ee..b16e92593 100644
--- a/common/amount.h
+++ b/common/amount.h
@@ -53,6 +53,10 @@ struct amount_sat amount_sat(u64 satoshis);
 WARN_UNUSED_RESULT bool amount_sat_to_msat(struct amount_msat *msat,
 					   struct amount_sat sat);
 
+/* You may not always be able to convert millisatoshis->satoshis without rounding. */
+WARN_UNUSED_RESULT bool amount_msat_to_sat(struct amount_sat *sat,
+					   struct amount_msat msat);
+
 /* You can always truncate millisatoshis->satoshis. */
 struct amount_sat amount_msat_to_sat_round_down(struct amount_msat msat);