diff --git a/sn0int-registry/src/models.rs b/sn0int-registry/src/models.rs
index 504e6d79..cf57efbd 100644
--- a/sn0int-registry/src/models.rs
+++ b/sn0int-registry/src/models.rs
@@ -231,13 +231,21 @@ impl Release {
         */
     }
 
-    pub fn find(id: i32, version: &str, connection: &PgConnection) -> Result<Release> {
-        releases::table.filter(releases::columns::module_id.eq(id))
+    pub fn find(module_id: i32, version: &str, connection: &PgConnection) -> Result<Release> {
+        releases::table.filter(releases::columns::module_id.eq(module_id))
                         .filter(releases::columns::version.eq(version))
                         .first::<Release>(connection)
                         .map_err(Error::from)
     }
 
+    pub fn try_find(module_id: i32, version: &str, connection: &PgConnection) -> Result<Option<Release>> {
+        releases::table.filter(releases::columns::module_id.eq(module_id))
+                        .filter(releases::columns::version.eq(version))
+                        .first::<Release>(connection)
+                        .optional()
+                        .map_err(Error::from)
+    }
+
     pub fn id(id: i32, connection: &PgConnection) -> Result<Release> {
         releases::table.find(id)
             .first::<Release>(connection)
diff --git a/sn0int-registry/src/routes/api.rs b/sn0int-registry/src/routes/api.rs
index f54e4728..bdabaea1 100644
--- a/sn0int-registry/src/routes/api.rs
+++ b/sn0int-registry/src/routes/api.rs
@@ -93,7 +93,17 @@ fn publish(name: String, upload: Json<PublishRequest>, session: AuthHeader, conn
 
     connection.transaction::<_, Error, _>(|| {
         let module = Module::update_or_create(&user, &name, &metadata.description, &connection)?;
-        module.add_version(&version, &upload.code, &connection)?;
+
+        match Release::try_find(module.id, &version, &connection)? {
+            Some(release) => {
+                // if the code is identical, pretend we published the version
+                if release.code != upload.code {
+                    bail!("Version number already in use")
+                }
+            },
+            None => module.add_version(&version, &upload.code, &connection)?,
+        }
+
         Ok(())
     })?;
 
diff --git a/src/api.rs b/src/api.rs
index 465fc3e7..76301045 100644
--- a/src/api.rs
+++ b/src/api.rs
@@ -40,7 +40,7 @@ impl Client {
 
     pub fn request<T: DeserializeOwned + fmt::Debug>(&self, mut request: RequestBuilder, body: Body) -> Result<T> {
         if let Some(session) = &self.session {
-            info!("Adding session token");
+            info!("Adding session token to request");
             request.header("Auth", session.as_str());
         }