diff --git a/Sources/App/Core/Gitlab.swift b/Sources/App/Core/Gitlab.swift
index 14f50080a..baca2a87a 100644
--- a/Sources/App/Core/Gitlab.swift
+++ b/Sources/App/Core/Gitlab.swift
@@ -105,8 +105,12 @@ extension Gitlab.Builder {
                 "VERSION_ID": versionID.uuidString
             ]
         )
-        let body = try JSONEncoder().encode(dto)
-        let response = try await httpClient.post(url: "\(projectURL)/trigger/pipeline", body: body)
+        let body = try URLEncodedFormEncoder().encode(dto)
+        let response = try await httpClient.post(
+            url: "\(projectURL)/trigger/pipeline",
+            headers: .contentTypeFormURLEncoded,
+            body: Data(body.utf8)
+        )
 
         do {
             guard let body = response.body else { throw Gitlab.Error.noBody }
@@ -205,6 +209,10 @@ private extension HTTPHeaders {
     static func bearer(_ token: String) -> Self {
         .init([("Authorization", "Bearer \(token)")])
     }
+
+    static var contentTypeFormURLEncoded: Self {
+        .init([("Content-Type", "application/x-www-form-urlencoded")])
+    }
 }
 
 
diff --git a/Tests/AppTests/BuildTests.swift b/Tests/AppTests/BuildTests.swift
index 0e4048d15..70b1ecaf8 100644
--- a/Tests/AppTests/BuildTests.swift
+++ b/Tests/AppTests/BuildTests.swift
@@ -145,7 +145,7 @@ class BuildTests: AppTestCase {
                 called.setTrue()
                 let body = try XCTUnwrap(body)
                 XCTAssertEqual(
-                    try JSONDecoder().decode(Gitlab.Builder.PostDTO.self, from: body),
+                    try URLEncodedFormDecoder().decode(Gitlab.Builder.PostDTO.self, from: body),
                     .init(token: "pipeline token",
                           ref: "main",
                           variables: [
@@ -201,7 +201,7 @@ class BuildTests: AppTestCase {
                 called.setTrue()
                 let body = try XCTUnwrap(body)
                 // only test the TIMEOUT value, the rest is already tested in `test_trigger` above
-                let response = try? JSONDecoder().decode(Gitlab.Builder.PostDTO.self, from: body)
+                let response = try? URLEncodedFormDecoder().decode(Gitlab.Builder.PostDTO.self, from: body)
                 XCTAssertNotNil(response)
                 XCTAssertEqual(response?.variables["TIMEOUT"], "15m")
                 return try .created(jsonEncode: Gitlab.Builder.Response.init(webUrl: "http://web_url"))
diff --git a/Tests/AppTests/BuildTriggerTests.swift b/Tests/AppTests/BuildTriggerTests.swift
index cedb9540d..70cb3a3f8 100644
--- a/Tests/AppTests/BuildTriggerTests.swift
+++ b/Tests/AppTests/BuildTriggerTests.swift
@@ -341,6 +341,7 @@ class BuildTriggerTests: AppTestCase {
     }
 
     func test_triggerBuildsUnchecked() async throws {
+        let queries = QueueIsolated<[Gitlab.Builder.PostDTO]>([])
         try await withDependencies {
             $0.environment.awsDocsBucket = { "awsDocsBucket" }
             $0.environment.builderToken = { "builder token" }
@@ -349,26 +350,15 @@ class BuildTriggerTests: AppTestCase {
             $0.environment.siteURL = { "http://example.com" }
             // Use live dependency but replace actual client with a mock so we can
             // assert on the details being sent without actually making a request
-            $0.buildSystem.triggerBuild = { @Sendable buildId, cloneURL, isDocBuild, platform, ref, swiftVersion, versionID in
-                try await Gitlab.Builder.triggerBuild(buildId: buildId,
-                                                      cloneURL: cloneURL,
-                                                      isDocBuild: isDocBuild,
-                                                      platform: platform,
-                                                      reference: ref,
-                                                      swiftVersion: swiftVersion,
-                                                      versionID: versionID)
+            $0.buildSystem.triggerBuild = BuildSystemClient.liveValue.triggerBuild
+            $0.httpClient.post = { @Sendable _, _, body in
+                let body = try XCTUnwrap(body)
+                let query = try URLEncodedFormDecoder().decode(Gitlab.Builder.PostDTO.self, from: body)
+                queries.withValue { $0.append(query) }
+                return try .created(jsonEncode: Gitlab.Builder.Response.init(webUrl: "http://web_url"))
             }
         } operation: {
             // setup
-            let queries = QueueIsolated<[Gitlab.Builder.PostDTO]>([])
-            let client = MockClient { req, res in
-                guard let query = try? req.query.decode(Gitlab.Builder.PostDTO.self) else { return }
-                queries.withValue { $0.append(query) }
-                try? res.content.encode(
-                    Gitlab.Builder.Response.init(webUrl: "http://web_url")
-                )
-            }
-
             let versionId = UUID()
             do {  // save package with partially completed builds
                 let p = Package(id: UUID(), url: "2")
@@ -381,7 +371,7 @@ class BuildTriggerTests: AppTestCase {
 
             // MUT
             try await triggerBuildsUnchecked(on: app.db,
-                                             client: client,
+                                             client: app.client,
                                              triggers: triggers)
 
             // validate
diff --git a/Tests/AppTests/GitlabBuilderTests.swift b/Tests/AppTests/GitlabBuilderTests.swift
index 61b20b7d5..6b45d695e 100644
--- a/Tests/AppTests/GitlabBuilderTests.swift
+++ b/Tests/AppTests/GitlabBuilderTests.swift
@@ -175,11 +175,13 @@ class LiveGitlabBuilderTests: AppTestCase {
                 // Set this to a valid value if you want to report build results back to the server
                 ProcessInfo.processInfo.environment["LIVE_BUILDER_TOKEN"]
             }
+            $0.environment.buildTimeout = { 10 }
             $0.environment.gitlabPipelineToken = {
                 // This Gitlab token is required in order to trigger the pipeline
                 ProcessInfo.processInfo.environment["LIVE_GITLAB_PIPELINE_TOKEN"]
             }
             $0.environment.siteURL = { "https://staging.swiftpackageindex.com" }
+            $0.httpClient = .liveValue
         } operation: {
             // set build branch to trigger on
             Gitlab.Builder.branch = "main"
@@ -198,7 +200,8 @@ class LiveGitlabBuilderTests: AppTestCase {
                 platform: .macosSpm,
                 reference: .tag(.init(0, 3, 2)),
                 swiftVersion: .v4,
-                versionID: versionID)
+                versionID: versionID
+            )
 
             print("status: \(res.status)")
             print("buildId: \(buildId)")
diff --git a/Tests/AppTests/Helpers/URLEncodedFormDecoder+ext.swift b/Tests/AppTests/Helpers/URLEncodedFormDecoder+ext.swift
new file mode 100644
index 000000000..568b80b2d
--- /dev/null
+++ b/Tests/AppTests/Helpers/URLEncodedFormDecoder+ext.swift
@@ -0,0 +1,22 @@
+// Copyright Dave Verwer, Sven A. Schmidt, and other contributors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import Vapor
+
+
+extension URLEncodedFormDecoder {
+    func decode<D: Decodable>(_: D.Type, from data: Data) throws -> D {
+        try self.decode(D.self, from: String(decoding: data, as: UTF8.self), userInfo: [:])
+    }
+}