diff --git a/Fixtures/TestProject/GeneratedProject.xcodeproj/project.pbxproj b/Fixtures/TestProject/GeneratedProject.xcodeproj/project.pbxproj
index ce7e60b9..e3d1e4c9 100644
--- a/Fixtures/TestProject/GeneratedProject.xcodeproj/project.pbxproj
+++ b/Fixtures/TestProject/GeneratedProject.xcodeproj/project.pbxproj
@@ -1,6 +1,5 @@
 // !$*UTF8*$!
 {
-	archiveVersion = 1;
 	classes = {
 	};
 	objectVersion = 46;
@@ -44,13 +43,11 @@
 /* Begin PBXCopyFilesBuildPhase section */
 		CFBP50493301 /* CopyFiles */ = {
 			isa = PBXCopyFilesBuildPhase;
-			buildActionMask = 2147483647;
 			dstPath = "";
 			dstSubfolderSpec = 10;
 			files = (
 				BF3862341101 /* MyFramework.framework in CopyFiles */,
 			);
-			runOnlyForDeploymentPostprocessing = 0;
 		};
 /* End PBXCopyFilesBuildPhase section */
 
@@ -191,7 +188,6 @@
 			buildActionMask = 2147483647;
 			files = (
 			);
-			runOnlyForDeploymentPostprocessing = 0;
 		};
 		HBP299349701 /* Frameworks */ = {
 			isa = PBXHeadersBuildPhase;
@@ -199,14 +195,12 @@
 			files = (
 				BF3515549501 /* MyFramework.h in Headers */,
 			);
-			runOnlyForDeploymentPostprocessing = 0;
 		};
 		HBP652326301 /* Frameworks */ = {
 			isa = PBXHeadersBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
 			);
-			runOnlyForDeploymentPostprocessing = 0;
 		};
 /* End PBXHeadersBuildPhase section */
 
@@ -297,14 +291,12 @@
 			buildActionMask = 2147483647;
 			files = (
 			);
-			runOnlyForDeploymentPostprocessing = 0;
 		};
 		RBP299349701 /* Resources */ = {
 			isa = PBXResourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
 			);
-			runOnlyForDeploymentPostprocessing = 0;
 		};
 		RBP652326301 /* Resources */ = {
 			isa = PBXResourcesBuildPhase;
@@ -315,7 +307,6 @@
 				BF2513089601 /* LocalizedStoryboard.storyboard in Resources */,
 				BF2250910101 /* Main.storyboard in Resources */,
 			);
-			runOnlyForDeploymentPostprocessing = 0;
 		};
 /* End PBXResourcesBuildPhase section */
 
@@ -387,7 +378,6 @@
 			files = (
 				BF9001417701 /* TestProjectTests.swift in Sources */,
 			);
-			runOnlyForDeploymentPostprocessing = 0;
 		};
 		SBP299349701 /* Sources */ = {
 			isa = PBXSourcesBuildPhase;
@@ -395,7 +385,6 @@
 			files = (
 				BF9155249601 /* FrameworkFile.swift in Sources */,
 			);
-			runOnlyForDeploymentPostprocessing = 0;
 		};
 		SBP652326301 /* Sources */ = {
 			isa = PBXSourcesBuildPhase;
@@ -404,7 +393,6 @@
 				BF1073850101 /* AppDelegate.swift in Sources */,
 				BF1744565901 /* ViewController.swift in Sources */,
 			);
-			runOnlyForDeploymentPostprocessing = 0;
 		};
 /* End PBXSourcesBuildPhase section */
 
@@ -704,7 +692,6 @@
 				XCBC89077001 /* Debug */,
 				XCBC60448901 /* Release */,
 			);
-			defaultConfigurationIsVisible = 0;
 			defaultConfigurationName = "";
 		};
 		XCCL29934901 /* Build configuration list for PBXNativeTarget "MyFramework" */ = {
@@ -713,7 +700,6 @@
 				XCBC19846901 /* Debug */,
 				XCBC89204001 /* Release */,
 			);
-			defaultConfigurationIsVisible = 0;
 			defaultConfigurationName = "";
 		};
 		XCCL65232601 /* Build configuration list for PBXNativeTarget "TestProject" */ = {
@@ -722,7 +708,6 @@
 				XCBC37128501 /* Debug */,
 				XCBC86437501 /* Release */,
 			);
-			defaultConfigurationIsVisible = 0;
 			defaultConfigurationName = "";
 		};
 		XCCL81399401 /* Build configuration list for PBXProject "GeneratedProject" */ = {
diff --git a/Package.resolved b/Package.resolved
index 58535b03..0fd79d68 100644
--- a/Package.resolved
+++ b/Package.resolved
@@ -69,8 +69,8 @@
         "repositoryURL": "https://github.com/xcodeswift/xcproj.git",
         "state": {
           "branch": null,
-          "revision": "cd1c329c6e092fdf5afbddf10dd59da564293aa6",
-          "version": "0.4.1"
+          "revision": "fc8cbfce8a6bc1a98773181afe8da97c2516b722",
+          "version": "1.2.0"
         }
       }
     ]
diff --git a/Package.swift b/Package.swift
index d1e588f1..2a7a0ff3 100644
--- a/Package.swift
+++ b/Package.swift
@@ -15,7 +15,7 @@ let package = Package(
         .package(url: "https://github.com/yonaskolb/JSONUtilities.git", from: "3.3.0"),
         .package(url: "https://github.com/kylef/Spectre.git", from: "0.7.0"),
         .package(url: "https://github.com/onevcat/Rainbow.git", from: "2.1.0"),
-        .package(url: "https://github.com/xcodeswift/xcproj.git", from: "0.1.2"),
+        .package(url: "https://github.com/xcodeswift/xcproj.git", from: "1.0.0"),
     ],
     targets: [
         .target(name: "XcodeGen", dependencies: [
diff --git a/Sources/XcodeGenKit/PBXProjGenerator.swift b/Sources/XcodeGenKit/PBXProjGenerator.swift
index 6c50eb1a..0d4b72ac 100644
--- a/Sources/XcodeGenKit/PBXProjGenerator.swift
+++ b/Sources/XcodeGenKit/PBXProjGenerator.swift
@@ -62,7 +62,7 @@ public class PBXProjGenerator {
 
     public func generate() throws -> PBXProj {
         uuids = []
-        project = PBXProj(archiveVersion: 1, objectVersion: 46, rootObject: generateUUID(PBXProject.self, spec.name))
+        project = PBXProj(objectVersion: 46, rootObject: generateUUID(PBXProject.self, spec.name))
 
         for group in spec.fileGroups {
             _ = try getGroups(path: spec.basePath + group)
@@ -250,7 +250,7 @@ public class PBXProjGenerator {
 
                 if (dependencyTarget.type.isLibrary || dependencyTarget.type.isFramework) && dependency.link {
                     let dependencyBuildFile = targetBuildFiles[dependencyTargetName]!
-                    let buildFile = PBXBuildFile(reference: generateUUID(PBXBuildFile.self, dependencyBuildFile.reference + target.name), fileRef: dependencyBuildFile.fileRef)
+                    let buildFile = PBXBuildFile(reference: generateUUID(PBXBuildFile.self, dependencyBuildFile.reference + target.name), fileRef: dependencyBuildFile.fileRef!)
                     addObject(buildFile)
                     targetFrameworkBuildFiles.append(buildFile.reference)
                 }
@@ -425,11 +425,11 @@ public class PBXProjGenerator {
 
         let nativeTarget = PBXNativeTarget(
             reference: targetNativeReferences[target.name]!,
+            name: target.name,
             buildConfigurationList: buildConfigList.reference,
             buildPhases: buildPhases,
             buildRules: [],
             dependencies: dependencies,
-            name: target.name,
             productReference: fileReference,
             productType: target.type)
         addObject(nativeTarget)
@@ -548,7 +548,7 @@ public class PBXProjGenerator {
 
                 // find base localisation variant group
                 let name = path.lastComponentWithoutExtension
-                let variantGroup = baseLocalisationVariantGroups.first { Path($0.name).lastComponentWithoutExtension == name }
+                let variantGroup = baseLocalisationVariantGroups.first { Path($0.name!).lastComponentWithoutExtension == name }
 
                 let fileReference: String
                 if let cachedFileReference = fileReferencesByPath[path] {
diff --git a/Tests/XcodeGenKitTests/ProjectGeneratorTests.swift b/Tests/XcodeGenKitTests/ProjectGeneratorTests.swift
index cd7244ee..19ca62a1 100644
--- a/Tests/XcodeGenKitTests/ProjectGeneratorTests.swift
+++ b/Tests/XcodeGenKitTests/ProjectGeneratorTests.swift
@@ -34,7 +34,8 @@ func projectGeneratorTests() {
                 let spec = ProjectSpec(basePath: "", name: "test", targets: [framework], options: options)
                 let project = try getProject(spec)
                 guard let target = project.pbxproj.nativeTargets.first,
-                    let buildConfigs = project.pbxproj.configurationLists.getReference(target.buildConfigurationList),
+                    let buildConfigList = target.buildConfigurationList,
+                    let buildConfigs = project.pbxproj.configurationLists.getReference(buildConfigList),
                     let buildConfigReference = buildConfigs.buildConfigurations.first,
                     let buildConfig = project.pbxproj.buildConfigurations.getReference(buildConfigReference) else {
                         throw failure("Build Config not found")