diff --git a/Sources/ProjectSpec/BuildScript.swift b/Sources/ProjectSpec/BuildScript.swift
index 14cfce0d..f1eaf33a 100644
--- a/Sources/ProjectSpec/BuildScript.swift
+++ b/Sources/ProjectSpec/BuildScript.swift
@@ -2,6 +2,8 @@ import Foundation
 import JSONUtilities
 
 public struct BuildScript: Equatable {
+    public static let runOnlyWhenInstallingDefault = false
+    public static let showEnvVarsDefault = true
 
     public var script: ScriptType
     public var name: String?
@@ -26,8 +28,8 @@ public struct BuildScript: Equatable {
         inputFileLists: [String] = [],
         outputFileLists: [String] = [],
         shell: String? = nil,
-        runOnlyWhenInstalling: Bool = false,
-        showEnvVars: Bool = true
+        runOnlyWhenInstalling: Bool = runOnlyWhenInstallingDefault,
+        showEnvVars: Bool = showEnvVarsDefault
     ) {
         self.script = script
         self.name = name
@@ -57,8 +59,8 @@ extension BuildScript: JSONObjectConvertible {
             script = .path(path)
         }
         shell = jsonDictionary.json(atKeyPath: "shell")
-        runOnlyWhenInstalling = jsonDictionary.json(atKeyPath: "runOnlyWhenInstalling") ?? false
-        showEnvVars = jsonDictionary.json(atKeyPath: "showEnvVars") ?? true
+        runOnlyWhenInstalling = jsonDictionary.json(atKeyPath: "runOnlyWhenInstalling") ?? BuildScript.runOnlyWhenInstallingDefault
+        showEnvVars = jsonDictionary.json(atKeyPath: "showEnvVars") ?? BuildScript.showEnvVarsDefault
     }
 }
 extension BuildScript: JSONEncodable {
@@ -73,7 +75,7 @@ extension BuildScript: JSONEncodable {
             "shell": shell
         ]
 
-        if !showEnvVars {
+        if showEnvVars != BuildScript.showEnvVarsDefault {
             dict["showEnvVars"] = showEnvVars
         }
 
diff --git a/Sources/ProjectSpec/Dependency.swift b/Sources/ProjectSpec/Dependency.swift
index 121fff2d..8da36e6d 100644
--- a/Sources/ProjectSpec/Dependency.swift
+++ b/Sources/ProjectSpec/Dependency.swift
@@ -2,15 +2,18 @@ import Foundation
 import JSONUtilities
 
 public struct Dependency: Equatable {
+    public static let removeHeadersDefault = true
+    public static let implicitDefault = false
+    public static let weakLinkDefault = false
 
     public var type: DependencyType
     public var reference: String
     public var embed: Bool?
     public var codeSign: Bool?
-    public var removeHeaders: Bool = true
+    public var removeHeaders: Bool = removeHeadersDefault
     public var link: Bool?
-    public var implicit: Bool = false
-    public var weakLink: Bool = false
+    public var implicit: Bool = implicitDefault
+    public var weakLink: Bool = weakLinkDefault
 
     public init(
         type: DependencyType,
@@ -18,8 +21,8 @@ public struct Dependency: Equatable {
         embed: Bool? = nil,
         codeSign: Bool? = nil,
         link: Bool? = nil,
-        implicit: Bool = false,
-        weakLink: Bool = false
+        implicit: Bool = implicitDefault,
+        weakLink: Bool = weakLinkDefault
     ) {
         self.type = type
         self.reference = reference
@@ -89,13 +92,13 @@ extension Dependency: JSONEncodable {
             "link": link
         ]
 
-        if !removeHeaders {
+        if removeHeaders != Dependency.removeHeadersDefault {
             dict["removeHeaders"] = removeHeaders
         }
-        if implicit {
+        if implicit != Dependency.implicitDefault {
             dict["implicit"] = implicit
         }
-        if weakLink {
+        if weakLink != Dependency.weakLinkDefault {
             dict["weak"] = weakLink
         }
 
diff --git a/Sources/ProjectSpec/Scheme.swift b/Sources/ProjectSpec/Scheme.swift
index 67c8ffba..58e6c56c 100644
--- a/Sources/ProjectSpec/Scheme.swift
+++ b/Sources/ProjectSpec/Scheme.swift
@@ -44,6 +44,9 @@ public struct Scheme: Equatable {
     }
 
     public struct Build: Equatable {
+        public static let parallelizeBuildDefault = true
+        public static let buildImplicitDependenciesDefault = true
+
         public var targets: [BuildTarget]
         public var parallelizeBuild: Bool
         public var buildImplicitDependencies: Bool
@@ -51,8 +54,8 @@ public struct Scheme: Equatable {
         public var postActions: [ExecutionAction]
         public init(
             targets: [BuildTarget],
-            parallelizeBuild: Bool = true,
-            buildImplicitDependencies: Bool = true,
+            parallelizeBuild: Bool = parallelizeBuildDefault,
+            buildImplicitDependencies: Bool = buildImplicitDependenciesDefault,
             preActions: [ExecutionAction] = [],
             postActions: [ExecutionAction] = []
         ) {
@@ -86,6 +89,8 @@ public struct Scheme: Equatable {
     }
 
     public struct Test: BuildAction {
+        public static let gatherCoverageDataDefault = false
+
         public var config: String?
         public var gatherCoverageData: Bool
         public var commandLineArguments: [String: Bool]
@@ -95,14 +100,17 @@ public struct Scheme: Equatable {
         public var environmentVariables: [XCScheme.EnvironmentVariable]
 
         public struct TestTarget: Equatable, ExpressibleByStringLiteral {
+            public static let randomExecutionOrderDefault = false
+            public static let parallelizableDefault = false
+
             public let name: String
             public var randomExecutionOrder: Bool
             public var parallelizable: Bool
 
             public init(
                 name: String,
-                randomExecutionOrder: Bool = false,
-                parallelizable: Bool = false
+                randomExecutionOrder: Bool = randomExecutionOrderDefault,
+                parallelizable: Bool = parallelizableDefault
             ) {
                 self.name = name
                 self.randomExecutionOrder = randomExecutionOrder
@@ -118,7 +126,7 @@ public struct Scheme: Equatable {
 
         public init(
             config: String,
-            gatherCoverageData: Bool = false,
+            gatherCoverageData: Bool = gatherCoverageDataDefault,
             randomExecutionOrder: Bool = false,
             parallelizable: Bool = false,
             commandLineArguments: [String: Bool] = [:],
@@ -174,6 +182,8 @@ public struct Scheme: Equatable {
     }
 
     public struct Archive: BuildAction {
+        public static let revealArchiveInOrganizerDefault = true
+        
         public var config: String?
         public var customArchiveName: String?
         public var revealArchiveInOrganizer: Bool
@@ -182,7 +192,7 @@ public struct Scheme: Equatable {
         public init(
             config: String,
             customArchiveName: String? = nil,
-            revealArchiveInOrganizer: Bool = true,
+            revealArchiveInOrganizer: Bool = revealArchiveInOrganizerDefault,
             preActions: [ExecutionAction] = [],
             postActions: [ExecutionAction] = []
         ) {
@@ -255,7 +265,7 @@ extension Scheme.Test: JSONObjectConvertible {
 
     public init(jsonDictionary: JSONDictionary) throws {
         config = jsonDictionary.json(atKeyPath: "config")
-        gatherCoverageData = jsonDictionary.json(atKeyPath: "gatherCoverageData") ?? false
+        gatherCoverageData = jsonDictionary.json(atKeyPath: "gatherCoverageData") ?? Scheme.Test.gatherCoverageDataDefault
         commandLineArguments = jsonDictionary.json(atKeyPath: "commandLineArguments") ?? [:]
         if let targets = jsonDictionary["targets"] as? [Any] {
             self.targets = try targets.compactMap { target in
@@ -294,8 +304,8 @@ extension Scheme.Test.TestTarget: JSONObjectConvertible {
 
     public init(jsonDictionary: JSONDictionary) throws {
         name = try jsonDictionary.json(atKeyPath: "name")
-        randomExecutionOrder = jsonDictionary.json(atKeyPath: "randomExecutionOrder") ?? false
-        parallelizable = jsonDictionary.json(atKeyPath: "parallelizable") ?? false
+        randomExecutionOrder = jsonDictionary.json(atKeyPath: "randomExecutionOrder") ?? Scheme.Test.TestTarget.randomExecutionOrderDefault
+        parallelizable = jsonDictionary.json(atKeyPath: "parallelizable") ?? Scheme.Test.TestTarget.parallelizableDefault
     }
 }
 
@@ -309,11 +319,11 @@ extension Scheme.Test.TestTarget: JSONEncodable {
             "name": name
         ]
 
-        if randomExecutionOrder {
-            dict["randomExecutionOrder"] = true
+        if randomExecutionOrder != Scheme.Test.TestTarget.randomExecutionOrderDefault {
+            dict["randomExecutionOrder"] = randomExecutionOrder
         }
-        if parallelizable {
-            dict["parallelizable"] = true
+        if parallelizable != Scheme.Test.TestTarget.parallelizableDefault {
+            dict["parallelizable"] = parallelizable
         }
 
         return dict
@@ -363,7 +373,7 @@ extension Scheme.Archive: JSONObjectConvertible {
     public init(jsonDictionary: JSONDictionary) throws {
         config = jsonDictionary.json(atKeyPath: "config")
         customArchiveName = jsonDictionary.json(atKeyPath: "customArchiveName")
-        revealArchiveInOrganizer = jsonDictionary.json(atKeyPath: "revealArchiveInOrganizer") ?? true
+        revealArchiveInOrganizer = jsonDictionary.json(atKeyPath: "revealArchiveInOrganizer") ?? Scheme.Archive.revealArchiveInOrganizerDefault
         preActions = jsonDictionary.json(atKeyPath: "preActions") ?? []
         postActions = jsonDictionary.json(atKeyPath: "postActions") ?? []
     }
@@ -378,7 +388,7 @@ extension Scheme.Archive: JSONEncodable {
             "customArchiveName": customArchiveName,
         ]
 
-        if !revealArchiveInOrganizer {
+        if revealArchiveInOrganizer != Scheme.Archive.revealArchiveInOrganizerDefault {
             dict["revealArchiveInOrganizer"] = revealArchiveInOrganizer
         }
 
@@ -439,8 +449,8 @@ extension Scheme.Build: JSONObjectConvertible {
         self.targets = targets.sorted { $0.target < $1.target }
         preActions = try jsonDictionary.json(atKeyPath: "preActions")?.map(Scheme.ExecutionAction.init) ?? []
         postActions = try jsonDictionary.json(atKeyPath: "postActions")?.map(Scheme.ExecutionAction.init) ?? []
-        parallelizeBuild = jsonDictionary.json(atKeyPath: "parallelizeBuild") ?? true
-        buildImplicitDependencies = jsonDictionary.json(atKeyPath: "buildImplicitDependencies") ?? true
+        parallelizeBuild = jsonDictionary.json(atKeyPath: "parallelizeBuild") ?? Scheme.Build.parallelizeBuildDefault
+        buildImplicitDependencies = jsonDictionary.json(atKeyPath: "buildImplicitDependencies") ?? Scheme.Build.buildImplicitDependenciesDefault
     }
 }
 
@@ -454,10 +464,10 @@ extension Scheme.Build: JSONEncodable {
             "postActions": postActions.map { $0.toJSONValue() },
         ]
 
-        if !parallelizeBuild {
+        if parallelizeBuild != Scheme.Build.parallelizeBuildDefault {
             dict["parallelizeBuild"] = parallelizeBuild
         }
-        if !buildImplicitDependencies {
+        if buildImplicitDependencies != Scheme.Build.buildImplicitDependenciesDefault {
             dict["buildImplicitDependencies"] = buildImplicitDependencies
         }
 
@@ -498,6 +508,7 @@ extension BuildType: JSONEncodable {
 }
 
 extension XCScheme.EnvironmentVariable: JSONObjectConvertible {
+    public static let enabledDefault = true
 
     private static func parseValue(_ value: Any) -> String {
         if let bool = value as? Bool {
@@ -517,7 +528,7 @@ extension XCScheme.EnvironmentVariable: JSONObjectConvertible {
             value = try jsonDictionary.json(atKeyPath: "value")
         }
         let variable: String = try jsonDictionary.json(atKeyPath: "variable")
-        let enabled: Bool = jsonDictionary.json(atKeyPath: "isEnabled") ?? true
+        let enabled: Bool = jsonDictionary.json(atKeyPath: "isEnabled") ?? XCScheme.EnvironmentVariable.enabledDefault
         self.init(variable: variable, value: value, enabled: enabled)
     }
 
@@ -536,10 +547,15 @@ extension XCScheme.EnvironmentVariable: JSONObjectConvertible {
 
 extension XCScheme.EnvironmentVariable: JSONEncodable {
     public func toJSONValue() -> Any {
-        return [
+        var dict: [String: Any] = [
             "variable": variable,
-            "value": value,
-            "isEnabled": enabled
+            "value": value
         ]
+
+        if enabled != XCScheme.EnvironmentVariable.enabledDefault {
+            dict["isEnabled"] = enabled
+        }
+
+        return dict
     }
 }
diff --git a/Sources/ProjectSpec/SpecOptions.swift b/Sources/ProjectSpec/SpecOptions.swift
index 020b0494..fc55641e 100644
--- a/Sources/ProjectSpec/SpecOptions.swift
+++ b/Sources/ProjectSpec/SpecOptions.swift
@@ -2,6 +2,12 @@ import Foundation
 import JSONUtilities
 
 public struct SpecOptions: Equatable {
+    public static let settingPresetsDefault = SettingPresets.all
+    public static let createIntermediateGroupsDefault = false
+    public static let transitivelyLinkDependenciesDefault = false
+    public static let groupSortPositionDefault = GroupSortPosition.bottom
+    public static let generateEmptyDirectoriesDefault = false
+    public static let findCarthageFrameworksDefault = false
 
     public var minimumXcodeGenVersion: Version?
     public var carthageBuildPath: String?
@@ -62,9 +68,9 @@ public struct SpecOptions: Equatable {
         minimumXcodeGenVersion: Version? = nil,
         carthageBuildPath: String? = nil,
         carthageExecutablePath: String? = nil,
-        createIntermediateGroups: Bool = false,
+        createIntermediateGroups: Bool = createIntermediateGroupsDefault,
         bundleIdPrefix: String? = nil,
-        settingPresets: SettingPresets = .all,
+        settingPresets: SettingPresets = settingPresetsDefault,
         developmentLanguage: String? = nil,
         indentWidth: UInt? = nil,
         tabWidth: UInt? = nil,
@@ -73,10 +79,10 @@ public struct SpecOptions: Equatable {
         deploymentTarget: DeploymentTarget = .init(),
         disabledValidations: [ValidationType] = [],
         defaultConfig: String? = nil,
-        transitivelyLinkDependencies: Bool = false,
-        groupSortPosition: GroupSortPosition = .bottom,
-        generateEmptyDirectories: Bool = false,
-        findCarthageFrameworks: Bool = false
+        transitivelyLinkDependencies: Bool = transitivelyLinkDependenciesDefault,
+        groupSortPosition: GroupSortPosition = groupSortPositionDefault,
+        generateEmptyDirectories: Bool = generateEmptyDirectoriesDefault,
+        findCarthageFrameworks: Bool = findCarthageFrameworksDefault
     ) {
         self.minimumXcodeGenVersion = minimumXcodeGenVersion
         self.carthageBuildPath = carthageBuildPath
@@ -109,8 +115,8 @@ extension SpecOptions: JSONObjectConvertible {
         carthageBuildPath = jsonDictionary.json(atKeyPath: "carthageBuildPath")
         carthageExecutablePath = jsonDictionary.json(atKeyPath: "carthageExecutablePath")
         bundleIdPrefix = jsonDictionary.json(atKeyPath: "bundleIdPrefix")
-        settingPresets = jsonDictionary.json(atKeyPath: "settingPresets") ?? .all
-        createIntermediateGroups = jsonDictionary.json(atKeyPath: "createIntermediateGroups") ?? false
+        settingPresets = jsonDictionary.json(atKeyPath: "settingPresets") ?? SpecOptions.settingPresetsDefault
+        createIntermediateGroups = jsonDictionary.json(atKeyPath: "createIntermediateGroups") ?? SpecOptions.createIntermediateGroupsDefault
         developmentLanguage = jsonDictionary.json(atKeyPath: "developmentLanguage")
         usesTabs = jsonDictionary.json(atKeyPath: "usesTabs")
         xcodeVersion = jsonDictionary.json(atKeyPath: "xcodeVersion")
@@ -119,10 +125,10 @@ extension SpecOptions: JSONObjectConvertible {
         deploymentTarget = jsonDictionary.json(atKeyPath: "deploymentTarget") ?? DeploymentTarget()
         disabledValidations = jsonDictionary.json(atKeyPath: "disabledValidations") ?? []
         defaultConfig = jsonDictionary.json(atKeyPath: "defaultConfig")
-        transitivelyLinkDependencies = jsonDictionary.json(atKeyPath: "transitivelyLinkDependencies") ?? false
-        groupSortPosition = jsonDictionary.json(atKeyPath: "groupSortPosition") ?? .bottom
-        generateEmptyDirectories = jsonDictionary.json(atKeyPath: "generateEmptyDirectories") ?? false
-        findCarthageFrameworks = jsonDictionary.json(atKeyPath: "findCarthageFrameworks") ?? false
+        transitivelyLinkDependencies = jsonDictionary.json(atKeyPath: "transitivelyLinkDependencies") ?? SpecOptions.transitivelyLinkDependenciesDefault
+        groupSortPosition = jsonDictionary.json(atKeyPath: "groupSortPosition") ?? SpecOptions.groupSortPositionDefault
+        generateEmptyDirectories = jsonDictionary.json(atKeyPath: "generateEmptyDirectories") ?? SpecOptions.generateEmptyDirectoriesDefault
+        findCarthageFrameworks = jsonDictionary.json(atKeyPath: "findCarthageFrameworks") ?? SpecOptions.findCarthageFrameworksDefault
     }
 }
 
@@ -145,16 +151,16 @@ extension SpecOptions: JSONEncodable {
             "defaultConfig": defaultConfig,
         ]
 
-        if settingPresets != .all {
+        if settingPresets != SpecOptions.settingPresetsDefault {
             dict["settingPresets"] = settingPresets.rawValue
         }
-        if createIntermediateGroups {
+        if createIntermediateGroups != SpecOptions.createIntermediateGroupsDefault {
             dict["createIntermediateGroups"] = createIntermediateGroups
         }
-        if generateEmptyDirectories {
+        if generateEmptyDirectories != SpecOptions.generateEmptyDirectoriesDefault {
             dict["generateEmptyDirectories"] = generateEmptyDirectories
         }
-        if findCarthageFrameworks {
+        if findCarthageFrameworks != SpecOptions.findCarthageFrameworksDefault {
             dict["findCarthageFrameworks"] = findCarthageFrameworks
         }
 
diff --git a/Sources/ProjectSpec/Target.swift b/Sources/ProjectSpec/Target.swift
index c529c554..403c5ed9 100644
--- a/Sources/ProjectSpec/Target.swift
+++ b/Sources/ProjectSpec/Target.swift
@@ -3,6 +3,8 @@ import JSONUtilities
 import xcodeproj
 
 public struct LegacyTarget: Equatable {
+    public static let passSettingsDefault = false
+
     public var toolPath: String
     public var arguments: String?
     public var passSettings: Bool
@@ -10,7 +12,7 @@ public struct LegacyTarget: Equatable {
 
     public init(
         toolPath: String,
-        passSettings: Bool = false,
+        passSettings: Bool = passSettingsDefault,
         arguments: String? = nil,
         workingDirectory: String? = nil
     ) {
@@ -267,19 +269,24 @@ extension LegacyTarget: JSONObjectConvertible {
     public init(jsonDictionary: JSONDictionary) throws {
         toolPath = try jsonDictionary.json(atKeyPath: "toolPath")
         arguments = jsonDictionary.json(atKeyPath: "arguments")
-        passSettings = jsonDictionary.json(atKeyPath: "passSettings") ?? false
+        passSettings = jsonDictionary.json(atKeyPath: "passSettings") ?? LegacyTarget.passSettingsDefault
         workingDirectory = jsonDictionary.json(atKeyPath: "workingDirectory")
     }
 }
 
 extension LegacyTarget: JSONEncodable {
     public func toJSONValue() -> Any {
-        return [
+        var dict: [String: Any?] = [
             "toolPath": toolPath,
-            "passSettings": passSettings,
             "arguments": arguments,
             "workingDirectory": workingDirectory,
-        ] as [String: Any?]
+        ]
+
+        if passSettings != LegacyTarget.passSettingsDefault {
+            dict["passSettings"] = passSettings
+        }
+
+        return dict
     }
 }
 
diff --git a/Sources/ProjectSpec/TargetScheme.swift b/Sources/ProjectSpec/TargetScheme.swift
index 5f906fb3..e059f6c5 100644
--- a/Sources/ProjectSpec/TargetScheme.swift
+++ b/Sources/ProjectSpec/TargetScheme.swift
@@ -3,6 +3,8 @@ import JSONUtilities
 import xcodeproj
 
 public struct TargetScheme: Equatable {
+    public static let gatherCoverageDataDefault = false
+
     public var testTargets: [Scheme.Test.TestTarget]
     public var configVariants: [String]
     public var gatherCoverageData: Bool
@@ -14,7 +16,7 @@ public struct TargetScheme: Equatable {
     public init(
         testTargets: [Scheme.Test.TestTarget] = [],
         configVariants: [String] = [],
-        gatherCoverageData: Bool = false,
+        gatherCoverageData: Bool = gatherCoverageDataDefault,
         commandLineArguments: [String: Bool] = [:],
         environmentVariables: [XCScheme.EnvironmentVariable] = [],
         preActions: [Scheme.ExecutionAction] = [],
@@ -47,7 +49,7 @@ extension TargetScheme: JSONObjectConvertible {
             testTargets = []
         }
         configVariants = jsonDictionary.json(atKeyPath: "configVariants") ?? []
-        gatherCoverageData = jsonDictionary.json(atKeyPath: "gatherCoverageData") ?? false
+        gatherCoverageData = jsonDictionary.json(atKeyPath: "gatherCoverageData") ?? TargetScheme.gatherCoverageDataDefault
         commandLineArguments = jsonDictionary.json(atKeyPath: "commandLineArguments") ?? [:]
         environmentVariables = try XCScheme.EnvironmentVariable.parseAll(jsonDictionary: jsonDictionary)
         preActions = jsonDictionary.json(atKeyPath: "preActions") ?? []
@@ -57,8 +59,7 @@ extension TargetScheme: JSONObjectConvertible {
 
 extension TargetScheme: JSONEncodable {
     public func toJSONValue() -> Any {
-        return [
-            "gatherCoverageData": gatherCoverageData,
+        var dict: [String: Any] = [
             "configVariants": configVariants,
             "commandLineArguments": commandLineArguments,
             "testTargets": testTargets.map { $0.toJSONValue() },
@@ -66,5 +67,11 @@ extension TargetScheme: JSONEncodable {
             "preActions": preActions.map { $0.toJSONValue() },
             "postActions": postActions.map { $0.toJSONValue() },
         ]
+        
+        if gatherCoverageData != TargetScheme.gatherCoverageDataDefault {
+            dict["gatherCoverageData"] = gatherCoverageData
+        }
+
+        return dict
     }
 }
diff --git a/Sources/ProjectSpec/TargetSource.swift b/Sources/ProjectSpec/TargetSource.swift
index 8669094a..e21dbe78 100644
--- a/Sources/ProjectSpec/TargetSource.swift
+++ b/Sources/ProjectSpec/TargetSource.swift
@@ -4,6 +4,7 @@ import PathKit
 import xcodeproj
 
 public struct TargetSource: Equatable {
+    public static let optionalDefault = false
 
     public var path: String
     public var name: String?
@@ -123,7 +124,7 @@ public struct TargetSource: Equatable {
         compilerFlags: [String] = [],
         excludes: [String] = [],
         type: SourceType? = nil,
-        optional: Bool = false,
+        optional: Bool = optionalDefault,
         buildPhase: BuildPhase? = nil,
         headerVisibility: HeaderVisibility? = nil,
         createIntermediateGroups: Bool? = nil
@@ -169,7 +170,7 @@ extension TargetSource: JSONObjectConvertible {
         headerVisibility = jsonDictionary.json(atKeyPath: "headerVisibility")
         excludes = jsonDictionary.json(atKeyPath: "excludes") ?? []
         type = jsonDictionary.json(atKeyPath: "type")
-        optional = jsonDictionary.json(atKeyPath: "optional") ?? false
+        optional = jsonDictionary.json(atKeyPath: "optional") ?? TargetSource.optionalDefault
 
         if let string: String = jsonDictionary.json(atKeyPath: "buildPhase") {
             buildPhase = try BuildPhase(string: string)
@@ -193,8 +194,8 @@ extension TargetSource: JSONEncodable {
             "createIntermediateGroups": createIntermediateGroups,
         ]
 
-        if optional {
-            dict["optional"] = true
+        if optional != TargetSource.optionalDefault {
+            dict["optional"] = optional
         }
 
         if dict.count == 0 {