diff --git a/core/src/errors/uploads.rs b/core/src/errors/uploads.rs
index 1e10e8c..faae1b3 100644
--- a/core/src/errors/uploads.rs
+++ b/core/src/errors/uploads.rs
@@ -2,6 +2,11 @@ use eva::{bytesize::ByteSize, data};
 
 use crate::types::{file, upload};
 
+#[data(error, display("unable to validate file class: {error}"))]
+pub struct UnableToValidateClass {
+    pub error: String,
+}
+
 #[data(error, copy, display("someone is finishing file already"))]
 #[derive(Default)]
 pub enum ConcurrentUploadInProgress {
diff --git a/core/src/requests/uploads.rs b/core/src/requests/uploads.rs
index cd5ebb2..dbcd0e4 100644
--- a/core/src/requests/uploads.rs
+++ b/core/src/requests/uploads.rs
@@ -67,6 +67,8 @@ pub mod finish {
 
     #[data(error)]
     pub enum Err {
+        #[display("{_0}")]
+        UnableToValidateClass(#[from] errors::uploads::UnableToValidateClass),
         #[display("{_0}")]
         NotFound(#[from] errors::uploads::NotFound),
         #[display("{_0}")]
diff --git a/http/src/requests/uploads.rs b/http/src/requests/uploads.rs
index 8d1d7b3..309898d 100644
--- a/http/src/requests/uploads.rs
+++ b/http/src/requests/uploads.rs
@@ -35,6 +35,7 @@ status_code::map!(reqs::finish::Err => [
     NotFound,
     Overuploading,
     ConcurrentUploadInProgress,
+    UnableToValidateClass,
 ]);
 
 #[data]
@@ -54,4 +55,5 @@ const _: () = {
     direct!(SimUpQuotaExceeded => TOO_MANY_REQUESTS);
     direct!(Overuploading => BAD_REQUEST);
     direct!(HashMismatch => BAD_REQUEST);
+    direct!(UnableToValidateClass => BAD_REQUEST);
 };