diff --git a/src/include/taler_exchange_service.h b/src/include/taler_exchange_service.h
index e61a07c91..02ab182f2 100644
--- a/src/include/taler_exchange_service.h
+++ b/src/include/taler_exchange_service.h
@@ -744,6 +744,32 @@ TALER_EXCHANGE_wire_cancel (struct TALER_EXCHANGE_WireHandle *wh);
 /* *********************  /coins/$COIN_PUB/deposit *********************** */
 
 
+/**
+ * Sign a deposit permission.  Function for wallets.
+ *
+ * @param amount the amount to be deposited
+ * @param deposit_fee the deposit fee we expect to pay
+ * @param h_wire hash of the merchant’s account details
+ * @param h_contract_terms hash of the contact of the merchant with the customer (further details are never disclosed to the exchange)
+ * @param coin_priv coin’s private key
+ * @param wallet_timestamp timestamp when the contract was finalized, must not be too far in the future
+ * @param merchant_pub the public key of the merchant (used to identify the merchant for refund requests)
+ * @param refund_deadline date until which the merchant can issue a refund to the customer via the exchange (can be zero if refunds are not allowed); must not be after the @a wire_deadline
+ * @param[out] coin_sig set to the signature made with purpose #TALER_SIGNATURE_WALLET_COIN_DEPOSIT
+ */
+void
+TALER_EXCHANGE_deposit_permission_sign (
+  const struct TALER_Amount *amount,
+  const struct TALER_Amount *deposit_fee,
+  const struct GNUNET_HashCode *h_wire,
+  const struct GNUNET_HashCode *h_contract_terms,
+  const struct TALER_CoinSpendPrivateKeyP *coin_priv,
+  struct GNUNET_TIME_Absolute wallet_timestamp,
+  const struct TALER_MerchantPublicKeyP *merchant_pub,
+  struct GNUNET_TIME_Absolute refund_deadline,
+  struct TALER_CoinSpendSignatureP *coin_sig);
+
+
 /**
  * @brief A Deposit Handle
  */
diff --git a/src/lib/exchange_api_deposit.c b/src/lib/exchange_api_deposit.c
index 276053658..351fa7a10 100644
--- a/src/lib/exchange_api_deposit.c
+++ b/src/lib/exchange_api_deposit.c
@@ -490,6 +490,59 @@ verify_signatures (const struct TALER_EXCHANGE_DenomPublicKey *dki,
 }
 
 
+/**
+ * Sign a deposit permission.  Function for wallets.
+ *
+ * @param amount the amount to be deposited
+ * @param deposit_fee the deposit fee we expect to pay
+ * @param h_wire hash of the merchant’s account details
+ * @param h_contract_terms hash of the contact of the merchant with the customer (further details are never disclosed to the exchange)
+ * @param coin_priv coin’s private key
+ * @param wallet_timestamp timestamp when the contract was finalized, must not be too far in the future
+ * @param merchant_pub the public key of the merchant (used to identify the merchant for refund requests)
+ * @param refund_deadline date until which the merchant can issue a refund to the customer via the exchange (can be zero if refunds are not allowed); must not be after the @a wire_deadline
+ * @param[out] coin_sig set to the signature made with purpose #TALER_SIGNATURE_WALLET_COIN_DEPOSIT
+ */
+void
+TALER_EXCHANGE_deposit_permission_sign (
+  const struct TALER_Amount *amount,
+  const struct TALER_Amount *deposit_fee,
+  const struct GNUNET_HashCode *h_wire,
+  const struct GNUNET_HashCode *h_contract_terms,
+  const struct TALER_CoinSpendPrivateKeyP *coin_priv,
+  struct GNUNET_TIME_Absolute wallet_timestamp,
+  const struct TALER_MerchantPublicKeyP *merchant_pub,
+  struct GNUNET_TIME_Absolute refund_deadline,
+  struct TALER_CoinSpendSignatureP *coin_sig)
+{
+  struct TALER_DepositRequestPS dr = {
+    .purpose.size = htonl
+                      (sizeof (dr)),
+    .purpose.purpose = htonl
+                         (TALER_SIGNATURE_WALLET_COIN_DEPOSIT),
+    .h_contract_terms = *h_contract_terms,
+    .h_wire = *h_wire,
+    .wallet_timestamp = GNUNET_TIME_absolute_hton (wallet_timestamp),
+    .refund_deadline = GNUNET_TIME_absolute_hton (refund_deadline),
+    .merchant = *merchant_pub
+  };
+
+  GNUNET_assert (GNUNET_OK ==
+                 GNUNET_TIME_round_abs (&wallet_timestamp));
+  GNUNET_assert (GNUNET_OK ==
+                 GNUNET_TIME_round_abs (&refund_deadline));
+  GNUNET_CRYPTO_eddsa_key_get_public (&coin_priv->eddsa_priv,
+                                      &dr.coin_pub.eddsa_pub);
+  TALER_amount_hton (&dr.amount_with_fee,
+                     amount);
+  TALER_amount_hton (&dr.deposit_fee,
+                     deposit_fee);
+  GNUNET_CRYPTO_eddsa_sign (&coin_priv->eddsa_priv,
+                            &dr,
+                            &coin_sig->eddsa_signature);
+}
+
+
 /**
  * Submit a deposit permission to the exchange and get the exchange's response.
  * Note that while we return the response verbatim to the caller for
diff --git a/src/testing/testing_api_cmd_deposit.c b/src/testing/testing_api_cmd_deposit.c
index f302a218b..e7a4c2988 100644
--- a/src/testing/testing_api_cmd_deposit.c
+++ b/src/testing/testing_api_cmd_deposit.c
@@ -394,39 +394,26 @@ deposit_run (void *cls,
   else
   {
     ds->refund_deadline = ds->wallet_timestamp;
-    wire_deadline = GNUNET_TIME_relative_to_absolute
-                      (GNUNET_TIME_UNIT_ZERO);
+    wire_deadline = GNUNET_TIME_relative_to_absolute (GNUNET_TIME_UNIT_ZERO);
   }
   GNUNET_CRYPTO_eddsa_key_get_public (&ds->merchant_priv.eddsa_priv,
                                       &merchant_pub.eddsa_pub);
-
   (void) GNUNET_TIME_round_abs (&wire_deadline);
-
-  // FIXME: This should be part of TALER_EXCHANGE_deposit()!
   {
-    struct TALER_DepositRequestPS dr;
+    struct GNUNET_HashCode h_wire;
 
-    memset (&dr, 0, sizeof (dr));
-    dr.purpose.size = htonl
-                        (sizeof (struct TALER_DepositRequestPS));
-    dr.purpose.purpose = htonl
-                           (TALER_SIGNATURE_WALLET_COIN_DEPOSIT);
-    dr.h_contract_terms = h_contract_terms;
     GNUNET_assert (GNUNET_OK ==
                    TALER_JSON_merchant_wire_signature_hash (ds->wire_details,
-                                                            &dr.h_wire));
-    dr.wallet_timestamp = GNUNET_TIME_absolute_hton (ds->wallet_timestamp);
-    dr.refund_deadline = GNUNET_TIME_absolute_hton
-                           (ds->refund_deadline);
-    TALER_amount_hton (&dr.amount_with_fee,
-                       &ds->amount);
-    TALER_amount_hton (&dr.deposit_fee,
-                       &denom_pub->fee_deposit);
-    dr.merchant = merchant_pub;
-    dr.coin_pub = coin_pub;
-    GNUNET_CRYPTO_eddsa_sign (&coin_priv->eddsa_priv,
-                              &dr,
-                              &coin_sig.eddsa_signature);
+                                                            &h_wire));
+    TALER_EXCHANGE_deposit_permission_sign (&ds->amount,
+                                            &denom_pub->fee_deposit,
+                                            &h_wire,
+                                            &h_contract_terms,
+                                            coin_priv,
+                                            ds->wallet_timestamp,
+                                            &merchant_pub,
+                                            ds->refund_deadline,
+                                            &coin_sig);
   }
   ds->dh = TALER_EXCHANGE_deposit (is->exchange,
                                    &ds->amount,