diff --git a/proxmox-rest-server/Cargo.toml b/proxmox-rest-server/Cargo.toml
index aea55f13..8fbbe8c0 100644
--- a/proxmox-rest-server/Cargo.toml
+++ b/proxmox-rest-server/Cargo.toml
@@ -7,7 +7,7 @@ description = "REST server implementation"
 
 # for example
 [dev-dependencies]
-proxmox-schema = { version = "1.1", features = [ "api-macro" ] }
+proxmox-schema = { version = "1.2", features = [ "api-macro" ] }
 tokio = { version = "1.6", features = [ "rt-multi-thread", "signal", "process" ] }
 
 [dependencies]
@@ -36,6 +36,6 @@ proxmox-io = "1"
 proxmox-lang = "1"
 proxmox-http = { version = "0.6", features = [ "client" ] }
 proxmox-router = "1.1"
-proxmox-schema = { version = "1.1", features = [ "api-macro", "upid-api-impl" ] }
+proxmox-schema = { version = "1.2", features = [ "api-macro", "upid-api-impl" ] }
 proxmox-time = "1"
 proxmox-sys = "0.2"
diff --git a/proxmox-rest-server/src/formatter.rs b/proxmox-rest-server/src/formatter.rs
index cb5774d5..e3958826 100644
--- a/proxmox-rest-server/src/formatter.rs
+++ b/proxmox-rest-server/src/formatter.rs
@@ -147,13 +147,14 @@ impl  OutputFormatter for ExtJsFormatter {
         let message: String;
         let mut errors = HashMap::new();
 
-        if let Some(param_err) = err.downcast_ref::<ParameterError>() {
-            for (name, err) in param_err.errors().iter() {
-                errors.insert(name, err.to_string());
+        match err.downcast::<ParameterError>() {
+            Ok(param_err) => {
+                for (name, err) in param_err {
+                    errors.insert(name, err.to_string());
+                }
+                message = String::from("parameter verification errors");
             }
-            message = String::from("parameter verification errors");
-        } else {
-            message = err.to_string();
+            Err(err) => message = err.to_string(),
         }
 
         let result = json!({