diff --git a/src/controllers/krate/publish.rs b/src/controllers/krate/publish.rs
index 004ea2df45a..41e79d6b851 100644
--- a/src/controllers/krate/publish.rs
+++ b/src/controllers/krate/publish.rs
@@ -157,6 +157,15 @@ pub async fn publish(app: AppState, req: BytesRequest) -> AppResult<Json<GoodCra
         validate_url(documentation.as_deref(), "documentation")?;
         validate_url(repository.as_deref(), "repository")?;
 
+        let categories = package
+            .categories
+            .map(|it| it.as_local().unwrap())
+            .unwrap_or_default();
+
+        if categories.len() > 5 {
+            return Err(cargo_err("expected at most 5 categories per crate"));
+        }
+
         // Create a transaction on the database, if there are no errors,
         // commit the transactions to record a new or updated crate.
         conn.transaction(|conn| {
@@ -172,11 +181,7 @@ pub async fn publish(app: AppState, req: BytesRequest) -> AppResult<Json<GoodCra
                 .iter()
                 .map(|s| s.as_str())
                 .collect::<Vec<_>>();
-            let categories = metadata
-                .categories
-                .iter()
-                .map(|s| s.as_str())
-                .collect::<Vec<_>>();
+            let categories = categories.iter().map(|s| s.as_str()).collect::<Vec<_>>();
 
             // Persist the new crate, if it doesn't already exist
             let persist = NewCrate {
diff --git a/src/tests/builders/publish.rs b/src/tests/builders/publish.rs
index a51ba34f71b..2e1dd6408f2 100644
--- a/src/tests/builders/publish.rs
+++ b/src/tests/builders/publish.rs
@@ -151,7 +151,6 @@ impl PublishBuilder {
                     .map(u::EncodableKeyword)
                     .collect(),
             ),
-            categories: u::EncodableCategoryList(self.categories.clone()),
         };
 
         let mut tarball_builder = TarballBuilder::new();
diff --git a/src/tests/krate/publish/snapshots/all__krate__publish__categories__too_many_categories.snap b/src/tests/krate/publish/snapshots/all__krate__publish__categories__too_many_categories.snap
index a7b65bb264c..5970faae56c 100644
--- a/src/tests/krate/publish/snapshots/all__krate__publish__categories__too_many_categories.snap
+++ b/src/tests/krate/publish/snapshots/all__krate__publish__categories__too_many_categories.snap
@@ -5,7 +5,7 @@ expression: response.into_json()
 {
   "errors": [
     {
-      "detail": "invalid upload request: invalid length 6, expected at most 5 categories per crate at line 1 column 155"
+      "detail": "expected at most 5 categories per crate"
     }
   ]
 }
diff --git a/src/tests/krate/publish/snapshots/all__krate__publish__keywords__too_many_keywords.snap b/src/tests/krate/publish/snapshots/all__krate__publish__keywords__too_many_keywords.snap
index cb921102eeb..5e183db775b 100644
--- a/src/tests/krate/publish/snapshots/all__krate__publish__keywords__too_many_keywords.snap
+++ b/src/tests/krate/publish/snapshots/all__krate__publish__keywords__too_many_keywords.snap
@@ -5,7 +5,7 @@ expression: response.into_json()
 {
   "errors": [
     {
-      "detail": "invalid upload request: invalid length 6, expected at most 5 keywords per crate at line 1 column 138"
+      "detail": "invalid upload request: invalid length 6, expected at most 5 keywords per crate at line 1 column 139"
     }
   ]
 }
diff --git a/src/views/krate_publish.rs b/src/views/krate_publish.rs
index 301c15ab89f..eb0cf0031eb 100644
--- a/src/views/krate_publish.rs
+++ b/src/views/krate_publish.rs
@@ -25,8 +25,6 @@ pub struct PublishMetadata {
     pub readme_file: Option<String>,
     #[serde(default)]
     pub keywords: EncodableKeywordList,
-    #[serde(default)]
-    pub categories: EncodableCategoryList,
 }
 
 #[derive(Serialize, Deserialize, Clone, Debug)]
@@ -195,21 +193,6 @@ impl<'de> Deserialize<'de> for EncodableKeywordList {
     }
 }
 
-#[derive(Serialize, Debug, Deref, Default)]
-pub struct EncodableCategoryList(pub Vec<String>);
-
-impl<'de> Deserialize<'de> for EncodableCategoryList {
-    fn deserialize<D: Deserializer<'de>>(d: D) -> Result<EncodableCategoryList, D::Error> {
-        let inner = <Vec<String> as Deserialize<'de>>::deserialize(d)?;
-        if inner.len() > 5 {
-            let expected = "at most 5 categories per crate";
-            Err(de::Error::invalid_length(inner.len(), &expected))
-        } else {
-            Ok(EncodableCategoryList(inner))
-        }
-    }
-}
-
 #[test]
 fn feature_deserializes_for_valid_features() {
     use serde_json as json;