diff --git a/integrations/actix/Cargo.toml b/integrations/actix/Cargo.toml
index 94a760f40..1128ee0c5 100644
--- a/integrations/actix/Cargo.toml
+++ b/integrations/actix/Cargo.toml
@@ -14,5 +14,6 @@ leptos = { workspace = true, features = ["ssr"] }
 leptos_meta = { workspace = true, features = ["ssr"] }
 leptos_router = { workspace = true, features = ["ssr"] }
 leptos_integration_utils = { workspace = true }
+serde_json = "1"
 parking_lot = "0.12.1"
 regex = "1.7.0"
diff --git a/integrations/actix/src/lib.rs b/integrations/actix/src/lib.rs
index 022d90edd..88ab30c7e 100644
--- a/integrations/actix/src/lib.rs
+++ b/integrations/actix/src/lib.rs
@@ -264,8 +264,10 @@ pub fn handle_server_fns_with_context(
                                 }
                             }
                         }
-                        Err(e) => HttpResponse::InternalServerError()
-                            .body(e.to_string()),
+                        Err(e) => HttpResponse::InternalServerError().body(
+                            serde_json::to_string(&e)
+                                .unwrap_or_else(|_| e.to_string()),
+                        ),
                     }
                 } else {
                     HttpResponse::BadRequest().body(format!(
diff --git a/integrations/axum/Cargo.toml b/integrations/axum/Cargo.toml
index a2a571787..361b93c08 100644
--- a/integrations/axum/Cargo.toml
+++ b/integrations/axum/Cargo.toml
@@ -16,5 +16,6 @@ leptos = { workspace = true, features = ["ssr"] }
 leptos_meta = { workspace = true, features = ["ssr"] }
 leptos_router = { workspace = true, features = ["ssr"] }
 leptos_integration_utils = { workspace = true }
+serde_json = "1"
 tokio = { version = "1", features = ["full"] }
 parking_lot = "0.12.1"
diff --git a/integrations/axum/src/lib.rs b/integrations/axum/src/lib.rs
index ddd983228..e73fdfced 100644
--- a/integrations/axum/src/lib.rs
+++ b/integrations/axum/src/lib.rs
@@ -411,7 +411,10 @@ async fn handle_server_fns_inner(
                                 }
                                 Err(e) => Response::builder()
                                     .status(StatusCode::INTERNAL_SERVER_ERROR)
-                                    .body(Full::from(e.to_string())),
+                                    .body(Full::from(
+                                        serde_json::to_string(&e)
+                                            .unwrap_or_else(|_| e.to_string()),
+                                    )),
                             }
                         } else {
                             Response::builder()
diff --git a/integrations/viz/Cargo.toml b/integrations/viz/Cargo.toml
index bebd68f2d..47c22cbec 100644
--- a/integrations/viz/Cargo.toml
+++ b/integrations/viz/Cargo.toml
@@ -16,5 +16,6 @@ leptos = { workspace = true, features = ["ssr"] }
 leptos_meta = { workspace = true, features = ["ssr"] }
 leptos_router = { workspace = true, features = ["ssr"] }
 leptos_integration_utils = { workspace = true }
+serde_json = "1"
 tokio = { version = "1", features = ["full"] }
 parking_lot = "0.12.1"
diff --git a/integrations/viz/src/lib.rs b/integrations/viz/src/lib.rs
index 823e087f6..a6db5358b 100644
--- a/integrations/viz/src/lib.rs
+++ b/integrations/viz/src/lib.rs
@@ -301,7 +301,10 @@ async fn handle_server_fns_inner(
                                 }
                                 Err(e) => Response::builder()
                                     .status(StatusCode::INTERNAL_SERVER_ERROR)
-                                    .body(Body::from(e.to_string())),
+                                    .body(Body::from(
+                                        serde_json::to_string(&e)
+                                            .unwrap_or_else(|_| e.to_string()),
+                                    )),
                             }
                         } else {
                             Response::builder()
diff --git a/leptos_server/src/lib.rs b/leptos_server/src/lib.rs
index 021950b4e..78ad1e24e 100644
--- a/leptos_server/src/lib.rs
+++ b/leptos_server/src/lib.rs
@@ -94,6 +94,7 @@ use std::{
 #[cfg(any(feature = "ssr", doc))]
 type ServerFnTraitObj = server_fn::ServerFnTraitObj<Scope>;
 
+#[allow(unused)]
 type ServerFunction = server_fn::ServerFunction<Scope>;
 
 #[cfg(any(feature = "ssr", doc))]
diff --git a/server_fn/src/lib.rs b/server_fn/src/lib.rs
index dfc87ac3b..f2b3f87b6 100644
--- a/server_fn/src/lib.rs
+++ b/server_fn/src/lib.rs
@@ -515,11 +515,13 @@ where
     #[cfg(not(target_arch = "wasm32"))]
     let status = status.as_u16();
     if (500..=599).contains(&status) {
+        let text = resp.text().await.unwrap_or_default();
         #[cfg(target_arch = "wasm32")]
         let status_text = resp.status_text();
         #[cfg(not(target_arch = "wasm32"))]
         let status_text = status.to_string();
-        return Err(ServerFnError::ServerError(status_text));
+        return Err(serde_json::from_str(&text)
+            .unwrap_or(ServerFnError::ServerError(status_text)));
     }
 
     // Decoding the body of the request