diff --git a/src/Serval/src/Serval.Client/Client.g.cs b/src/Serval/src/Serval.Client/Client.g.cs
index 9f382ca3..6766766a 100644
--- a/src/Serval/src/Serval.Client/Client.g.cs
+++ b/src/Serval/src/Serval.Client/Client.g.cs
@@ -4337,11 +4337,11 @@ public partial interface ITranslationEnginesClient
         /// Will completely replace corpus' file associations. Will not affect jobs already queued or running. Will not affect existing pretranslations until new build is complete.
         /// </remarks>
         /// <param name="id">The translation engine id</param>
-        /// <param name="corpusConfig">The corpus configuration</param>
         /// <param name="parallelCorpusId">The corpus id</param>
+        /// <param name="corpusConfig">The corpus configuration</param>
         /// <returns>The corpus was updated successfully</returns>
         /// <exception cref="ServalApiException">A server side error occurred.</exception>
-        System.Threading.Tasks.Task<TranslationCorpus> UpdateParallelCorpusAsync(string id, TranslationParallelCorpusUpdateConfig corpusConfig, string corpusId, string? parallelCorpusId = null, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
+        System.Threading.Tasks.Task<TranslationCorpus> UpdateParallelCorpusAsync(string id, string parallelCorpusId, TranslationParallelCorpusUpdateConfig corpusConfig, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
 
         /// <param name="cancellationToken">A cancellation token that can be used by other objects or threads to receive notice of cancellation.</param>
         /// <summary>
@@ -6376,17 +6376,17 @@ public string BaseUrl
         /// Will completely replace corpus' file associations. Will not affect jobs already queued or running. Will not affect existing pretranslations until new build is complete.
         /// </remarks>
         /// <param name="id">The translation engine id</param>
-        /// <param name="corpusConfig">The corpus configuration</param>
         /// <param name="parallelCorpusId">The corpus id</param>
+        /// <param name="corpusConfig">The corpus configuration</param>
         /// <returns>The corpus was updated successfully</returns>
         /// <exception cref="ServalApiException">A server side error occurred.</exception>
-        public virtual async System.Threading.Tasks.Task<TranslationCorpus> UpdateParallelCorpusAsync(string id, TranslationParallelCorpusUpdateConfig corpusConfig, string corpusId, string? parallelCorpusId = null, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken))
+        public virtual async System.Threading.Tasks.Task<TranslationCorpus> UpdateParallelCorpusAsync(string id, string parallelCorpusId, TranslationParallelCorpusUpdateConfig corpusConfig, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken))
         {
             if (id == null)
                 throw new System.ArgumentNullException("id");
 
-            if (corpusId == null)
-                throw new System.ArgumentNullException("corpusId");
+            if (parallelCorpusId == null)
+                throw new System.ArgumentNullException("parallelCorpusId");
 
             if (corpusConfig == null)
                 throw new System.ArgumentNullException("corpusConfig");
@@ -6406,17 +6406,11 @@ public string BaseUrl
 
                     var urlBuilder_ = new System.Text.StringBuilder();
                     if (!string.IsNullOrEmpty(_baseUrl)) urlBuilder_.Append(_baseUrl);
-                    // Operation Path: "translation/engines/{id}/parallel-corpora/{corpusId}"
+                    // Operation Path: "translation/engines/{id}/parallel-corpora/{parallelCorpusId}"
                     urlBuilder_.Append("translation/engines/");
                     urlBuilder_.Append(System.Uri.EscapeDataString(ConvertToString(id, System.Globalization.CultureInfo.InvariantCulture)));
                     urlBuilder_.Append("/parallel-corpora/");
-                    urlBuilder_.Append(System.Uri.EscapeDataString(ConvertToString(corpusId, System.Globalization.CultureInfo.InvariantCulture)));
-                    urlBuilder_.Append('?');
-                    if (parallelCorpusId != null)
-                    {
-                        urlBuilder_.Append(System.Uri.EscapeDataString("parallelCorpusId")).Append('=').Append(System.Uri.EscapeDataString(ConvertToString(parallelCorpusId, System.Globalization.CultureInfo.InvariantCulture))).Append('&');
-                    }
-                    urlBuilder_.Length--;
+                    urlBuilder_.Append(System.Uri.EscapeDataString(ConvertToString(parallelCorpusId, System.Globalization.CultureInfo.InvariantCulture)));
 
                     PrepareRequest(client_, request_, urlBuilder_);
 
diff --git a/src/Serval/src/Serval.Translation/Controllers/TranslationEnginesController.cs b/src/Serval/src/Serval.Translation/Controllers/TranslationEnginesController.cs
index 916e396a..3b2143bc 100644
--- a/src/Serval/src/Serval.Translation/Controllers/TranslationEnginesController.cs
+++ b/src/Serval/src/Serval.Translation/Controllers/TranslationEnginesController.cs
@@ -583,7 +583,7 @@ CancellationToken cancellationToken
     /// <response code="404">The engine or corpus does not exist.</response>
     /// <response code="503">A necessary service is currently unavailable. Check `/health` for more details.</response>
     [Authorize(Scopes.UpdateTranslationEngines)]
-    [HttpPatch("{id}/parallel-corpora/{corpusId}")]
+    [HttpPatch("{id}/parallel-corpora/{parallelCorpusId}")]
     [ProducesResponseType(StatusCodes.Status200OK)]
     [ProducesResponseType(typeof(void), StatusCodes.Status400BadRequest)]
     [ProducesResponseType(typeof(void), StatusCodes.Status401Unauthorized)]
diff --git a/src/Serval/test/Serval.ApiServer.IntegrationTests/TranslationEngineTests.cs b/src/Serval/test/Serval.ApiServer.IntegrationTests/TranslationEngineTests.cs
index d79d1e86..9c6cd528 100644
--- a/src/Serval/test/Serval.ApiServer.IntegrationTests/TranslationEngineTests.cs
+++ b/src/Serval/test/Serval.ApiServer.IntegrationTests/TranslationEngineTests.cs
@@ -645,8 +645,8 @@ string engineId
                 Assert.That(engine, Is.Not.Null);
                 Assert.Multiple(() =>
                 {
-                    Assert.That(engine.Corpora[0].SourceFiles[0].Filename, Is.EqualTo(FILE2_FILENAME));
-                    Assert.That(engine.Corpora[0].TargetFiles[0].Filename, Is.EqualTo(FILE1_FILENAME));
+                    Assert.That(engine.Corpora[0].SourceFiles[0].Filename, Is.EqualTo(FILE1_FILENAME));
+                    Assert.That(engine.Corpora[0].TargetFiles[0].Filename, Is.EqualTo(FILE2_FILENAME));
                 });
                 break;
             }
@@ -891,7 +891,7 @@ string engineId
                     SourceCorpusIds = [SOURCE_CORPUS_ID],
                     TargetCorpusIds = [TARGET_CORPUS_ID]
                 };
-                await client.UpdateParallelCorpusAsync(engineId, updateConfig, result.Id);
+                await client.UpdateParallelCorpusAsync(engineId, result.Id, updateConfig);
                 Engine? engine = await _env.Engines.GetAsync(engineId);
                 Assert.That(engine, Is.Not.Null);
                 Assert.Multiple(() =>
@@ -917,7 +917,7 @@ string engineId
                         SourceCorpusIds = [SOURCE_CORPUS_ID],
                         TargetCorpusIds = [TARGET_CORPUS_ID]
                     };
-                    await client.UpdateParallelCorpusAsync(engineId, updateConfig, DOES_NOT_EXIST_CORPUS_ID);
+                    await client.UpdateParallelCorpusAsync(engineId, DOES_NOT_EXIST_CORPUS_ID, updateConfig);
                 });
                 Assert.That(ex?.StatusCode, Is.EqualTo(expectedStatusCode));
                 break;