diff --git a/src/main.rs b/src/main.rs
index 38d7f14..e187c25 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -69,14 +69,19 @@ async fn main() {
     });
 
     let (router, mut api) = OpenApiRouter::new()
+        // Book API
         .routes(routes!(routes::book::get_book_by_ean))
         .routes(routes!(routes::book::get_book_by_id))
+        // Book Instance API
         .routes(routes!(routes::book_instance::get_book_instance_by_id))
         .routes(routes!(routes::book_instance::create_book_instance))
+        .routes(routes!(routes::book_instance::update_book_instance))
+        // Owner API
         .routes(routes!(routes::owner::get_owner_by_id))
         .routes(routes!(routes::owner::create_owner))
         .routes(routes!(routes::owner::update_owner))
         .routes(routes!(routes::owner::get_owners))
+        // Misc
         .routes(routes!(routes::websocket::ws_handler))
         .route("/", get(index))
         .with_state(shared_state)
diff --git a/src/routes/book_instance.rs b/src/routes/book_instance.rs
index eb635a8..7e10919 100644
--- a/src/routes/book_instance.rs
+++ b/src/routes/book_instance.rs
@@ -17,7 +17,7 @@ struct BookInstanceByIdParams(u32);
 #[axum::debug_handler]
 #[utoipa::path(
     get,
-    path = "/book_instance/id/{id}",
+    path = "/book_instance/{id}",
     params(BookInstanceByIdParams),
     responses(
         (status = OK, body = book_instance::Model, description = "Found book instance with corresponding ID in the database"),
@@ -79,3 +79,60 @@ pub async fn create_book_instance(
         Ok(res) => (StatusCode::OK, Json(Some(res.try_into_model().expect("All fields should be set once the book instance is saved"))))
     }
 }
+
+#[derive(Deserialize, Serialize, utoipa::ToSchema)]
+pub struct BookInstanceUpdateParams {
+    status: Option<book_instance::BookStatus>,
+    owner_id: Option<u32>,
+    price: Option<i32>,
+}
+
+#[axum::debug_handler]
+#[utoipa::path(
+    patch,
+    path = "/book_instance/{id}",
+    params(BookInstanceByIdParams),
+    request_body = BookInstanceUpdateParams,
+    responses(
+        (status = OK, body = book_instance::Model, description = "Successfully updated book instance"),
+        (status = NOT_FOUND, description = "No book instance with specified id was found"),
+    ),
+    summary = "Update a book instance",
+    description = "Update a book instance",
+    tag = "book-instance-api",
+)]
+pub async fn update_book_instance(
+    State(state): State<Arc<AppState>>,
+    Path(id): Path<u32>,
+    Json(instance_payload): Json<BookInstanceUpdateParams>,
+) -> (StatusCode, Json<Option<book_instance::Model>>) {
+
+    if let Ok(Some(book_instance)) = BookInstance::find_by_id(id).one(state.db_conn.as_ref()).await {
+        let mut book_instance: book_instance::ActiveModel = book_instance.into();
+        book_instance.price = match instance_payload.price {
+            None => book_instance.price,
+            Some(v) => Set(v)
+        };
+        book_instance.owner_id = match instance_payload.owner_id {
+            None => book_instance.owner_id,
+            Some(v) => Set(v)
+        };
+        book_instance.status = match instance_payload.status {
+            None => book_instance.status,
+            Some(v) => Set(v)
+        };
+        
+        match book_instance.update(state.db_conn.as_ref()).await {
+            Err(e) => {
+                log::error!(target: "api", "Error while updating book instance from api: {:#?}", e);
+                (StatusCode::INTERNAL_SERVER_ERROR, Json(None))
+            },
+            Ok(res) => {
+                let model = res.try_into_model().expect("All fields should be set once the book instance is saved");
+                (StatusCode::OK, Json(Some(model)))
+            }
+        }
+    } else {
+        (StatusCode::NOT_FOUND, Json(None))
+    }
+}