diff --git a/Sources/XcodeGenKit/SettingsBuilder.swift b/Sources/XcodeGenKit/SettingsBuilder.swift
index e5a98181..d4b406b5 100644
--- a/Sources/XcodeGenKit/SettingsBuilder.swift
+++ b/Sources/XcodeGenKit/SettingsBuilder.swift
@@ -158,8 +158,8 @@ extension SettingsPresetFile {
 
         if let symlink = try? bundlePath.symlinkDestination() {
             possibleSettingsPaths = [
-                symlink + relativePath
-                ] + possibleSettingsPaths
+                symlink + relativePath,
+            ] + possibleSettingsPaths
         }
 
         guard let settingsPath = possibleSettingsPaths.first(where: { $0.exists }) else {
diff --git a/Sources/XcodeGenKit/SourceGenerator.swift b/Sources/XcodeGenKit/SourceGenerator.swift
index 8327012b..77ec842f 100644
--- a/Sources/XcodeGenKit/SourceGenerator.swift
+++ b/Sources/XcodeGenKit/SourceGenerator.swift
@@ -96,7 +96,8 @@ class SourceGenerator {
     }
 
     func getFileReference(path: Path, inPath: Path, name: String? = nil, sourceTree: PBXSourceTree = .group, lastKnownFileType: String? = nil) -> String {
-        if let fileReference = fileReferencesByPath[path.string.lowercased()] {
+        let fileReferenceKey = path.string.lowercased()
+        if let fileReference = fileReferencesByPath[fileReferenceKey] {
             return fileReference
         } else {
             let fileReferencePath = path.byRemovingBase(path: inPath)
@@ -105,17 +106,44 @@ class SourceGenerator {
                 fileReferenceName = nil
             }
             let lastKnownFileType = lastKnownFileType ?? PBXFileReference.fileType(path: path)
-            let fileReference = createObject(
-                id: path.byRemovingBase(path: spec.basePath).string,
-                PBXFileReference(
+
+            if path.extension == "xcdatamodeld" {
+                let models = (try? path.children()) ?? []
+                let modelFileReference = models
+                    .filter { $0.extension == "xcdatamodel" }
+                    .sorted()
+                    .map { path in
+                        createObject(
+                            id: path.byRemovingBase(path: spec.basePath).string,
+                            PBXFileReference(
+                                sourceTree: .group,
+                                lastKnownFileType: "wrapper.xcdatamodel",
+                                path: path.lastComponent
+                            )
+                        )
+                }
+                let versionGroup = addObject(id: fileReferencePath.string, XCVersionGroup(
+                    currentVersion: modelFileReference.first?.reference,
+                    path: fileReferencePath.string,
                     sourceTree: sourceTree,
-                    name: fileReferenceName,
-                    lastKnownFileType: lastKnownFileType,
-                    path: fileReferencePath.string
+                    versionGroupType: "wrapper.xcdatamodel",
+                    children: modelFileReference.map { $0.reference }
+                ))
+                fileReferencesByPath[fileReferenceKey] = versionGroup
+                return versionGroup
+            } else {
+                let fileReference = createObject(
+                    id: path.byRemovingBase(path: spec.basePath).string,
+                    PBXFileReference(
+                        sourceTree: sourceTree,
+                        name: fileReferenceName,
+                        lastKnownFileType: lastKnownFileType,
+                        path: fileReferencePath.string
+                    )
                 )
-            )
-            fileReferencesByPath[path.string.lowercased()] = fileReference.reference
-            return fileReference.reference
+                fileReferencesByPath[fileReferenceKey] = fileReference.reference
+                return fileReference.reference
+            }
         }
     }
 
@@ -125,7 +153,7 @@ class SourceGenerator {
         }
         if let fileExtension = path.extension {
             switch fileExtension {
-            case "swift", "m", "mm", "cpp", "c", "S": return .sources
+            case "swift", "m", "mm", "cpp", "c", "S", "xcdatamodeld": return .sources
             case "h", "hh", "hpp", "ipp", "tpp", "hxx", "def": return .headers
             case "xcconfig", "entitlements", "gpx", "lproj", "apns": return nil
             default: return .resources
diff --git a/Tests/Fixtures/TestProject/App_iOS/Model.xcdatamodeld/Model.xcdatamodel/contents b/Tests/Fixtures/TestProject/App_iOS/Model.xcdatamodeld/Model.xcdatamodel/contents
new file mode 100644
index 00000000..a53d67bf
--- /dev/null
+++ b/Tests/Fixtures/TestProject/App_iOS/Model.xcdatamodeld/Model.xcdatamodel/contents
@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<model type="com.apple.IDECoreDataModeler.DataModel" documentVersion="1.0" lastSavedToolsVersion="13772" systemVersion="17D47" minimumToolsVersion="Automatic" sourceLanguage="Swift" userDefinedModelVersionIdentifier="">
+    <entity name="Entity" representedClassName="Entity" syncable="YES" codeGenerationType="class"/>
+    <elements>
+        <element name="Entity" positionX="-63" positionY="-18" width="128" height="45"/>
+    </elements>
+</model>
\ No newline at end of file
diff --git a/Tests/Fixtures/TestProject/Project.xcodeproj/project.pbxproj b/Tests/Fixtures/TestProject/Project.xcodeproj/project.pbxproj
index 2559e577..d3eeabdc 100644
--- a/Tests/Fixtures/TestProject/Project.xcodeproj/project.pbxproj
+++ b/Tests/Fixtures/TestProject/Project.xcodeproj/project.pbxproj
@@ -44,6 +44,7 @@
 		BF_561304997165 /* Standalone.swift in Sources */ = {isa = PBXBuildFile; fileRef = FR_675266829517 /* Standalone.swift */; };
 		BF_612351978356 /* Interface.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = VG_264279911176 /* Interface.storyboard */; };
 		BF_624802436672 /* FrameworkFile.swift in Sources */ = {isa = PBXBuildFile; fileRef = FR_172952167809 /* FrameworkFile.swift */; };
+		BF_670499288392 /* Model.xcdatamodeld in Sources */ = {isa = PBXBuildFile; fileRef = VG_229021855709 /* Model.xcdatamodeld */; settings = {COMPILER_FLAGS = "-Werror"; }; };
 		BF_681504666330 = {isa = PBXBuildFile; fileRef = FR_825232110500 /* App_iOS.app */; };
 		BF_721498080533 /* ResourceFolder in Resources */ = {isa = PBXBuildFile; fileRef = FR_257073931060 /* ResourceFolder */; };
 		BF_729846993631 /* Alamofire.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = FR_410645050443 /* Alamofire.framework */; };
@@ -163,6 +164,7 @@
 		FR_507023492251 /* App_watchOS Extension.appex */ = {isa = PBXFileReference; explicitFileType = "wrapper.app-extension"; includeInIndex = 0; path = "App_watchOS Extension.appex"; sourceTree = BUILT_PRODUCTS_DIR; };
 		FR_525119120469 /* Framework.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = Framework.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		FR_530852296303 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
+		FR_570918052822 /* Model.xcdatamodel */ = {isa = PBXFileReference; lastKnownFileType = wrapper.xcdatamodel; path = Model.xcdatamodel; sourceTree = "<group>"; };
 		FR_587738154368 /* Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = Assets.xcassets; sourceTree = "<group>"; };
 		FR_602633703434 /* en */ = {isa = PBXFileReference; lastKnownFileType = text.plist.strings; name = en; path = en.lproj/Localizable.stringsdict; sourceTree = "<group>"; };
 		FR_609193904586 /* Base */ = {isa = PBXFileReference; lastKnownFileType = file.storyboard; name = Base; path = Base.lproj/Main.storyboard; sourceTree = "<group>"; };
@@ -378,6 +380,7 @@
 				VG_746876637628 /* Localizable.stringsdict */,
 				VG_118219888726 /* LocalizedStoryboard.storyboard */,
 				VG_609193904586 /* Main.storyboard */,
+				VG_229021855709 /* Model.xcdatamodeld */,
 				FR_481575785861 /* ViewController.swift */,
 			);
 			name = App;
@@ -928,6 +931,7 @@
 			buildActionMask = 2147483647;
 			files = (
 				BF_892119987440 /* AppDelegate.swift in Sources */,
+				BF_670499288392 /* Model.xcdatamodeld in Sources */,
 				BF_503484983186 /* MoreUnder.swift in Sources */,
 				BF_561304997165 /* Standalone.swift in Sources */,
 				BF_331192862207 /* ViewController.swift in Sources */,
@@ -2677,6 +2681,19 @@
 			defaultConfigurationName = "Production Debug";
 		};
 /* End XCConfigurationList section */
+
+/* Begin XCVersionGroup section */
+		VG_229021855709 /* Model.xcdatamodeld */ = {
+			isa = XCVersionGroup;
+			children = (
+				FR_570918052822 /* Model.xcdatamodel */,
+			);
+			currentVersion = FR_570918052822 /* Model.xcdatamodel */;
+			path = Model.xcdatamodeld;
+			sourceTree = "<group>";
+			versionGroupType = wrapper.xcdatamodel;
+		};
+/* End XCVersionGroup section */
 	};
 	rootObject = P_8448771205358 /* Project object */;
 }
diff --git a/Tests/XcodeGenKitTests/FixtureTests.swift b/Tests/XcodeGenKitTests/FixtureTests.swift
index 897ad2e4..64114e46 100644
--- a/Tests/XcodeGenKitTests/FixtureTests.swift
+++ b/Tests/XcodeGenKitTests/FixtureTests.swift
@@ -11,11 +11,19 @@ func generate(specPath: Path, projectPath: Path) throws -> XcodeProj {
     let generator = ProjectGenerator(spec: spec)
     let project = try generator.generateProject()
     let oldProject = try XcodeProj(path: projectPath)
+    let pbxProjPath = projectPath + XcodeProj.pbxprojPath(projectPath)
+    let oldProjectString: String = try pbxProjPath.read()
     try project.write(path: projectPath, override: true)
+    let newProjectString: String = try pbxProjPath.read()
 
     let newProject = try XcodeProj(path: projectPath)
-    if newProject != oldProject {
-        throw failure("\(projectPath.string) has changed. If change is legitimate commit the change and run test again")
+    let stringDiff = newProjectString != oldProjectString
+    if newProject != oldProject || stringDiff {
+        var message = "\(projectPath.string) has changed. If change is legitimate commit the change and run test again"
+        if stringDiff {
+            message += ":\n\n\(pbxProjPath):\n\(prettyFirstDifferenceBetweenStrings(oldProjectString, newProjectString))"
+        }
+        throw failure(message)
     }
 
     return newProject
diff --git a/Tests/XcodeGenKitTests/ProjectGeneratorTests.swift b/Tests/XcodeGenKitTests/ProjectGeneratorTests.swift
index 65a746af..8fec2c26 100644
--- a/Tests/XcodeGenKitTests/ProjectGeneratorTests.swift
+++ b/Tests/XcodeGenKitTests/ProjectGeneratorTests.swift
@@ -452,6 +452,30 @@ func projectGeneratorTests() {
                 try project.expectFile(paths: ["Sources", "A", "B", "b.swift"], buildPhase: .sources)
             }
 
+            $0.it("generates core data models") {
+                let directories = """
+                Sources:
+                    model.xcdatamodeld:
+                        - model.xcdatamodel
+                """
+                try createDirectories(directories)
+
+                let target = Target(name: "Test", type: .application, platform: .iOS, sources: ["Sources"])
+                let spec = ProjectSpec(basePath: directoryPath, name: "Test", targets: [target])
+
+                let project = try getPbxProj(spec)
+                guard let fileReference = project.objects.fileReferences.first(where: { $0.value.nameOrPath == "model.xcdatamodel" }) else {
+                    throw failure("Couldn't find model file reference")
+                }
+                guard let versionGroup = project.objects.versionGroups.values.first else {
+                    throw failure("Couldn't find version group")
+                }
+                try expect(versionGroup.currentVersion) == fileReference.key
+                try expect(versionGroup.children) == [fileReference.key]
+                try expect(versionGroup.path) == "model.xcdatamodeld"
+                try expect(fileReference.value.path) == "model.xcdatamodel"
+            }
+
             $0.it("handles duplicate names") {
                 let directories = """
                 Sources:
diff --git a/Tests/XcodeGenKitTests/SpecLoadingTests.swift b/Tests/XcodeGenKitTests/SpecLoadingTests.swift
index 5679e071..71a5bd0c 100644
--- a/Tests/XcodeGenKitTests/SpecLoadingTests.swift
+++ b/Tests/XcodeGenKitTests/SpecLoadingTests.swift
@@ -173,7 +173,7 @@ func specLoadingTests() {
                             "name": "Before Build",
                             "settingsTarget": "Target1",
                         ],
-                    ]
+                    ],
                 ],
             ]
             let scheme = try Scheme(name: "Scheme", jsonDictionary: schemeDictionary)
diff --git a/Tests/XcodeGenKitTests/StringDiff.swift b/Tests/XcodeGenKitTests/StringDiff.swift
new file mode 100644
index 00000000..5e1970ea
--- /dev/null
+++ b/Tests/XcodeGenKitTests/StringDiff.swift
@@ -0,0 +1,99 @@
+//https://gist.github.com/kristopherjohnson/543687c763cd6e524c91
+
+import Foundation
+
+/// Find first differing character between two strings
+///
+/// :param: s1 First String
+/// :param: s2 Second String
+///
+/// :returns: .DifferenceAtIndex(i) or .NoDifference
+public func firstDifferenceBetweenStrings(_ s1: String, _ s2: String) -> FirstDifferenceResult {
+    let len1 = s1.count
+    let len2 = s2.count
+
+    let lenMin = min(len1, len2)
+
+    for i in 0..<lenMin {
+        if (s1 as NSString).character(at: i) != (s2 as NSString).character(at: i) {
+            return .DifferenceAtIndex(i)
+        }
+    }
+
+    if len1 < len2 {
+        return .DifferenceAtIndex(len1)
+    }
+
+    if len2 < len1 {
+        return .DifferenceAtIndex(len2)
+    }
+
+    return .NoDifference
+}
+
+
+/// Create a formatted String representation of difference between strings
+///
+/// :param: s1 First string
+/// :param: s2 Second string
+///
+/// :returns: a string, possibly containing significant whitespace and newlines
+public func prettyFirstDifferenceBetweenStrings(_ s1: String, _ s2: String, previewPrefixLength: Int = 25, previewSuffixLength:Int = 25) -> String {
+    let firstDifferenceResult = firstDifferenceBetweenStrings(s1, s2)
+
+    func diffString(at index: Int, _ s1: String, _ s2: String) -> String {
+        let markerArrow = "\u{2b06}"  // "⬆"
+        let ellipsis    = "\u{2026}"  // "…"
+
+        /// Given a string and a range, return a string representing that substring.
+        ///
+        /// If the range starts at a position other than 0, an ellipsis
+        /// will be included at the beginning.
+        ///
+        /// If the range ends before the actual end of the string,
+        /// an ellipsis is added at the end.
+        func windowSubstring(_ s: String, _ range: NSRange) -> String {
+            let validRange = NSMakeRange(range.location, min(range.length, s.count - range.location))
+            let substring = (s as NSString).substring(with: validRange)
+
+            let prefix = range.location > 0 ? ellipsis : ""
+            let suffix = (s.count - range.location > range.length) ? ellipsis : ""
+
+            return "\(prefix)\(substring)\(suffix)"
+        }
+
+        // Show this many characters before and after the first difference
+        let windowLength = previewPrefixLength + 1 + previewSuffixLength
+
+        let windowIndex = max(index - previewPrefixLength, 0)
+        let windowRange = NSMakeRange(windowIndex, windowLength)
+
+        let sub1 = windowSubstring(s1, windowRange)
+        let sub2 = windowSubstring(s2, windowRange)
+
+        let markerPosition = min(previewSuffixLength, index) + (windowIndex > 0 ? 1 : 0)
+
+        let markerPrefix = String(repeating: " ", count: markerPosition)
+        let markerLine = "\(markerPrefix)\(markerArrow)"
+
+        return "Difference at index \(index):\n\(sub1)\n\(sub2)\n\(markerLine)"
+    }
+
+    switch firstDifferenceResult {
+    case .NoDifference:                 return "No difference"
+    case .DifferenceAtIndex(let index): return diffString(at: index, s1, s2)
+    }
+}
+
+
+/// Result type for firstDifferenceBetweenStrings()
+public enum FirstDifferenceResult {
+    /// Strings are identical
+    case NoDifference
+
+    /// Strings differ at the specified index.
+    ///
+    /// This could mean that characters at the specified index are different,
+    /// or that one string is longer than the other
+    case DifferenceAtIndex(Int)
+}