diff --git a/src/model/activity/delivery.rs b/src/model/activity/delivery.rs
index abb4710..431a3bd 100644
--- a/src/model/activity/delivery.rs
+++ b/src/model/activity/delivery.rs
@@ -17,7 +17,7 @@ pub enum DeliveryErrorClass {
 
 #[derive(Debug, Error, Serialize)]
 #[error("Invalid delivery task definition: {}")]
-#[serde(tag = "type")]
+#[serde(tag = "type", content = "detail")]
 pub enum InvalidDeliveryTaskError {
     #[error("No signer with ID: {0}")]
     NoSuchSigner(String),
@@ -33,7 +33,7 @@ pub enum InvalidDeliveryTaskError {
 
 #[derive(Debug, Error, Serialize)]
 #[error("Retriable task delivery failure: {}")]
-#[serde(tag = "type")]
+#[serde(tag = "type", content = "detail")]
 pub enum RetriableLocalDeliveryTaskError {
     #[error("Signing error: {0}")]
     Signing(String),
@@ -45,7 +45,7 @@ pub enum RetriableLocalDeliveryTaskError {
 
 #[derive(Debug, Error, Serialize)]
 #[error("Retriable remote delivery error: {}")]
-#[serde(tag = "type")]
+#[serde(tag = "type", content = "detail")]
 pub enum RetriableRemoteDeliveryError {
     #[error("Timeout")]
     Timeout,
@@ -75,7 +75,7 @@ pub enum RetriableRemoteDeliveryError {
 
 #[derive(Debug, Error, Serialize)]
 #[error("Hard remote delivery error: {}")]
-#[serde(tag = "type")]
+#[serde(tag = "type", content = "detail")]
 pub enum HardRemoteDeliveryError {
     #[error("Gone")]
     Gone,
@@ -98,7 +98,7 @@ pub struct DeliveryError {
 }
 
 #[derive(Debug, Error, Serialize)]
-#[serde(tag = "type")]
+#[serde(tag = "type", content = "detail")]
 pub enum DeliveryErrorKind {
     #[error(transparent)]
     InvalidTask(#[from] InvalidDeliveryTaskError),
@@ -231,11 +231,13 @@ impl From<reqwest::Error> for DeliveryErrorKind {
         }
 
         match value {
-            e if e.is_connect() => RetriableRemoteDeliveryError::Connect(e.to_string()).into(),
+            e if e.is_connect() => RetriableRemoteDeliveryError::Connect(format!("{:?}", e)).into(),
             e if e.is_timeout() => RetriableRemoteDeliveryError::Timeout.into(),
-            e if e.is_decode() => RetriableRemoteDeliveryError::ResponseParse(e.to_string()).into(),
-            e if e.is_builder() => InvalidDeliveryTaskError::Reqwest(e.to_string()).into(),
-            e => RetriableRemoteDeliveryError::GenericReqwest(e.to_string()).into(),
+            e if e.is_decode() => {
+                RetriableRemoteDeliveryError::ResponseParse(format!("{:?}", e)).into()
+            }
+            e if e.is_builder() => InvalidDeliveryTaskError::Reqwest(format!("{:?}", e)).into(),
+            e => RetriableRemoteDeliveryError::GenericReqwest(format!("{:?}", e)).into(),
         }
     }
 }