diff --git a/fints4k/src/main/kotlin/net/dankito/fints/messages/segmente/implementierte/sepa/SepaBankTransferBase.kt b/fints4k/src/main/kotlin/net/dankito/fints/messages/segmente/implementierte/sepa/SepaBankTransferBase.kt
index 8c400d5f..4b4e4acf 100644
--- a/fints4k/src/main/kotlin/net/dankito/fints/messages/segmente/implementierte/sepa/SepaBankTransferBase.kt
+++ b/fints4k/src/main/kotlin/net/dankito/fints/messages/segmente/implementierte/sepa/SepaBankTransferBase.kt
@@ -33,7 +33,7 @@ open class SepaBankTransferBase(
         "CreditorIban" to data.creditorIban.replace(" ", ""),
         "CreditorBic" to data.creditorBic.replace(" ", ""),
         "Amount" to data.amount.toString(), // TODO: check if ',' or '.' should be used as decimal separator
-        "Usage" to messageCreator.convertToAllowedCharacters(data.usage),
+        "Usage" to if (data.usage.isEmpty()) " " else messageCreator.convertToAllowedCharacters(data.usage),
         "RequestedExecutionDate" to RequestedExecutionDateValueForNotScheduledTransfers
     ),
     messageCreator