diff --git a/Sources/SWBTaskConstruction/TaskProducers/BuildPhaseTaskProducers/CopyFilesTaskProducer.swift b/Sources/SWBTaskConstruction/TaskProducers/BuildPhaseTaskProducers/CopyFilesTaskProducer.swift
index 559c1e20..54daab89 100644
--- a/Sources/SWBTaskConstruction/TaskProducers/BuildPhaseTaskProducers/CopyFilesTaskProducer.swift
+++ b/Sources/SWBTaskConstruction/TaskProducers/BuildPhaseTaskProducers/CopyFilesTaskProducer.swift
@@ -169,9 +169,15 @@ class CopyFilesTaskProducer: FilesBasedBuildPhaseTaskProducerBase, FilesBasedBui
     override func constructTasksForRule(_ rule: any BuildRuleAction, _ group: FileToBuildGroup, _ buildFilesContext: BuildFilesProcessingContext, _ scope: MacroEvaluationScope, _ delegate: any TaskGenerationDelegate) async {
         let dstFolder = computeOutputDirectory(scope)
 
-        // FIXME: Merge the region variant.
+        // Merge the region variant.
+        // Since this behavior was not always here, some people have hardcoded lproj directories in their destination folder path.
+        // Only add an additional component if there isn't one already.
+        var locDST = dstFolder
+        if !locDST.containsRegionVariantPathComponent {
+            locDST = dstFolder.join(group.regionVariantPathComponent)
+        }
 
-        let cbc = CommandBuildContext(producer: context, scope: scope, inputs: group.files, isPreferredArch: buildFilesContext.belongsToPreferredArch, buildPhaseInfo: buildFilesContext.buildPhaseInfo(for: rule), resourcesDir: dstFolder, unlocalizedResourcesDir: dstFolder)
+        let cbc = CommandBuildContext(producer: context, scope: scope, inputs: group.files, isPreferredArch: buildFilesContext.belongsToPreferredArch, buildPhaseInfo: buildFilesContext.buildPhaseInfo(for: rule), resourcesDir: locDST, unlocalizedResourcesDir: dstFolder)
         await constructTasksForRule(rule, cbc, delegate)
     }
 
diff --git a/Sources/SWBUtil/Path.swift b/Sources/SWBUtil/Path.swift
index 28294f29..94bf7134 100644
--- a/Sources/SWBUtil/Path.swift
+++ b/Sources/SWBUtil/Path.swift
@@ -404,6 +404,24 @@ public struct Path: Serializable, Sendable {
         return nil
     }
 
+    /// `true` if the path contains any .lproj directories as path components.
+    public var containsRegionVariantPathComponent: Bool {
+        var path = self.join("File.strings") // since regionVariantName looks at parent dir
+        while !path.isRoot && !path.isEmpty {
+            if path.regionVariantName != nil {
+                return true
+            } else {
+                let parent = path.dirname
+                if parent == path {
+                    break
+                } else {
+                    path = parent
+                }
+            }
+        }
+        return false
+    }
+
     /// Return true if the pathname is conformant to path restrictions on the platform.
     ///
     /// Check the Unicode string representation of the path for reserved characters that cannot be represented as a path.
diff --git a/Tests/SWBTaskConstructionTests/InstallLocTaskConstructionTests.swift b/Tests/SWBTaskConstructionTests/InstallLocTaskConstructionTests.swift
index 83432e46..0cd157d0 100644
--- a/Tests/SWBTaskConstructionTests/InstallLocTaskConstructionTests.swift
+++ b/Tests/SWBTaskConstructionTests/InstallLocTaskConstructionTests.swift
@@ -1014,6 +1014,83 @@ fileprivate struct InstallLocTaskConstructionTests: CoreBasedTests {
         }
     }
 
+    @Test(.requireSDKs(.macOS))
+    func copyFilesRulesMergeRegion() async throws {
+        let testProject = TestProject(
+            "aProject",
+            groupTree: TestGroup(
+                "SomeFiles", path: "Sources",
+                children: [
+                    TestVariantGroup("Localizable.strings", children: [
+                        TestFile("en.lproj/Localizable.strings", regionVariantName: "en"),
+                        TestFile("ja.lproj/Localizable.strings", regionVariantName: "ja"),
+                        TestFile("zh_TW.lproj/Localizable.strings", regionVariantName: "zh_TW"),
+                    ]),
+                ]),
+            buildConfigurations: [
+                TestBuildConfiguration(
+                    "Debug",
+                    buildSettings: [
+                        "PRODUCT_NAME": "$(TARGET_NAME)",
+                        "GENERATE_INFOPLIST_FILE": "YES",
+                        "APPLY_RULES_IN_COPY_FILES": "YES"
+                    ]),
+            ],
+            targets: [
+                TestStandardTarget(
+                    "CoreFoo", type: .framework,
+                    buildPhases: [
+                        TestCopyFilesBuildPhase([
+                            "Localizable.strings",
+                        ], destinationSubfolder: .absolute, destinationSubpath: "/System/Library/Bundles/MyBundle.bundle", onlyForDeployment: true),
+                        TestCopyFilesBuildPhase([
+                            "Localizable.strings",
+                        ], destinationSubfolder: .builtProductsDir, destinationSubpath: "OtherProduct.bundle", onlyForDeployment: false),
+                    ]
+                )
+            ])
+        let tester = try await TaskConstructionTester(getCore(), testProject)
+
+        // installloc single language
+        await tester.checkBuild(BuildParameters(action: .installLoc, configuration: "Release", overrides: ["INSTALLLOC_LANGUAGE": "ja"]), runDestination: .macOS) { results in
+            results.checkTarget("CoreFoo") { target in
+                results.checkTaskExists(.matchTarget(target), .matchRule(["Copy", "/tmp/Test/aProject/build/Debug/OtherProduct.bundle/ja.lproj/Localizable.strings", "/tmp/Test/aProject/Sources/ja.lproj/Localizable.strings"]))
+                results.checkTaskExists(.matchTarget(target), .matchRule(["Copy", "/tmp/aProject.dst/System/Library/Bundles/MyBundle.bundle/ja.lproj/Localizable.strings", "/tmp/Test/aProject/Sources/ja.lproj/Localizable.strings"]))
+            }
+
+            results.checkNoDiagnostics()
+        }
+
+        // installloc multi-language
+        await tester.checkBuild(BuildParameters(action: .installLoc, configuration: "Release", overrides: ["INSTALLLOC_LANGUAGE": "ja zh_TW"]), runDestination: .macOS) { results in
+            results.checkTarget("CoreFoo") { target in
+                results.checkTaskExists(.matchTarget(target), .matchRule(["Copy", "/tmp/Test/aProject/build/Debug/OtherProduct.bundle/ja.lproj/Localizable.strings", "/tmp/Test/aProject/Sources/ja.lproj/Localizable.strings"]))
+                results.checkTaskExists(.matchTarget(target), .matchRule(["Copy", "/tmp/aProject.dst/System/Library/Bundles/MyBundle.bundle/ja.lproj/Localizable.strings", "/tmp/Test/aProject/Sources/ja.lproj/Localizable.strings"]))
+
+                results.checkTaskExists(.matchTarget(target), .matchRule(["Copy", "/tmp/Test/aProject/build/Debug/OtherProduct.bundle/zh_TW.lproj/Localizable.strings", "/tmp/Test/aProject/Sources/zh_TW.lproj/Localizable.strings"]))
+                results.checkTaskExists(.matchTarget(target), .matchRule(["Copy", "/tmp/aProject.dst/System/Library/Bundles/MyBundle.bundle/zh_TW.lproj/Localizable.strings", "/tmp/Test/aProject/Sources/zh_TW.lproj/Localizable.strings"]))
+            }
+
+            results.checkNoDiagnostics()
+        }
+
+        // install
+        await tester.checkBuild(BuildParameters(action: .install, configuration: "Release"), runDestination: .macOS) { results in
+            results.checkTarget("CoreFoo") { target in
+                results.checkTaskExists(.matchTarget(target), .matchRule(["CopyStringsFile", "/tmp/Test/aProject/build/Debug/OtherProduct.bundle/en.lproj/Localizable.strings", "/tmp/Test/aProject/Sources/en.lproj/Localizable.strings"]))
+                results.checkTaskExists(.matchTarget(target), .matchRule(["CopyStringsFile", "/tmp/aProject.dst/System/Library/Bundles/MyBundle.bundle/en.lproj/Localizable.strings", "/tmp/Test/aProject/Sources/en.lproj/Localizable.strings"]))
+
+                results.checkTaskExists(.matchTarget(target), .matchRule(["CopyStringsFile", "/tmp/Test/aProject/build/Debug/OtherProduct.bundle/ja.lproj/Localizable.strings", "/tmp/Test/aProject/Sources/ja.lproj/Localizable.strings"]))
+                results.checkTaskExists(.matchTarget(target), .matchRule(["CopyStringsFile", "/tmp/aProject.dst/System/Library/Bundles/MyBundle.bundle/ja.lproj/Localizable.strings", "/tmp/Test/aProject/Sources/ja.lproj/Localizable.strings"]))
+
+                results.checkTaskExists(.matchTarget(target), .matchRule(["CopyStringsFile", "/tmp/Test/aProject/build/Debug/OtherProduct.bundle/zh_TW.lproj/Localizable.strings", "/tmp/Test/aProject/Sources/zh_TW.lproj/Localizable.strings"]))
+                results.checkTaskExists(.matchTarget(target), .matchRule(["CopyStringsFile", "/tmp/aProject.dst/System/Library/Bundles/MyBundle.bundle/zh_TW.lproj/Localizable.strings", "/tmp/Test/aProject/Sources/zh_TW.lproj/Localizable.strings"]))
+            }
+
+            results.checkNoDiagnostics()
+        }
+    }
+
     @Test(.requireSDKs(.iOS))
     func installLocForFramework() async throws {
         let testProject = TestProject(