diff --git a/Sources/geometrize/GeometrizeModelBase.swift b/Sources/geometrize/GeometrizeModelBase.swift
index 0180c7d..8f9b3f3 100644
--- a/Sources/geometrize/GeometrizeModelBase.swift
+++ b/Sources/geometrize/GeometrizeModelBase.swift
@@ -44,7 +44,7 @@ class GeometrizeModelBase {
     ///   - shape: The shape to draw.
     ///   - color: The color (including alpha) of the shape.
     /// - Returns: Data about the shape drawn on the model.
-    func draw(shape: any Shape, color: Rgba) -> ShapeResult {
+    func draw(shape: Shape, color: Rgba) -> ShapeResult {
         let lines: [Scanline] = shape.rasterize(x: 0...width - 1, y: 0...height - 1)
         let before: Bitmap = currentBitmap
         currentBitmap.draw(lines: lines, color: color)
diff --git a/Sources/geometrize/SVGExporter.swift b/Sources/geometrize/SVGExporter.swift
index 1c16ba3..50f00dc 100644
--- a/Sources/geometrize/SVGExporter.swift
+++ b/Sources/geometrize/SVGExporter.swift
@@ -13,7 +13,7 @@ public struct SVGExporter {
     ///   - color: The color of the shape
     ///   - shape: The shape to convert to SVG data
     /// - Returns: The SVG shape data for the given shape
-    func singleShapeData(color: Rgba, shape: any Shape) -> String {
+    func singleShapeData(color: Rgba, shape: Shape) -> String {
         var shapeData: String = shapeData(shape: shape)
 
         var styles: String = ""
@@ -45,7 +45,7 @@ public struct SVGExporter {
     /// - Returns: A string representing the SVG image.
     func exportSingleShape( // swiftlint:disable:this function_parameter_count
         color: Rgba,
-        shape: any Shape,
+        shape: Shape,
         width: Int,
         height: Int,
         originWidth: Int,
@@ -142,7 +142,7 @@ public struct SVGExporter {
         "<path d=\"M\(Int(q.x1)) \(Int(q.y1)) Q\(Int(q.cx)) \(Int(q.cy)) \(Int(q.x2)) \(Int(q.y2))\" \(svg_style_hook)/>"
     }
 
-    private func shapeData(shape: any Shape) -> String {
+    private func shapeData(shape: Shape) -> String {
         switch shape {
         case let rectangle as Rectangle:
             return shapeData(rectangle: rectangle)
diff --git a/Sources/geometrize/ShapeAcceptancePrecondition.swift b/Sources/geometrize/ShapeAcceptancePrecondition.swift
index 7ee5604..8a92209 100644
--- a/Sources/geometrize/ShapeAcceptancePrecondition.swift
+++ b/Sources/geometrize/ShapeAcceptancePrecondition.swift
@@ -14,7 +14,7 @@ import Foundation
 public typealias ShapeAcceptancePreconditionFunction = @Sendable (
     _ lastScore: Double,
     _ newScore: Double,
-    _ shape: any Shape,
+    _ shape: Shape,
     _ lines: [Scanline],
     _ color: Rgba,
     _ before: Bitmap,
@@ -25,7 +25,7 @@ public typealias ShapeAcceptancePreconditionFunction = @Sendable (
 @Sendable public func defaultAddShapePrecondition( // swiftlint:disable:this function_parameter_count
     lastScore: Double,
     newScore: Double,
-    shape: any Shape,
+    shape: Shape,
     lines: [Scanline],
     color: Rgba,
     _: Bitmap,
diff --git a/Sources/geometrize/ShapeCreator.swift b/Sources/geometrize/ShapeCreator.swift
index fc7de4e..368f819 100644
--- a/Sources/geometrize/ShapeCreator.swift
+++ b/Sources/geometrize/ShapeCreator.swift
@@ -1,6 +1,6 @@
 import Foundation
 
-public typealias ShapeCreator = @Sendable (inout SplitMix64) -> any Shape
+public typealias ShapeCreator = @Sendable (inout SplitMix64) -> Shape
 
 /// Creates a function for creating instances of  Shape. Returned instances should be set up!
 /// - Parameters:
diff --git a/Sources/geometrize/ShapeResult.swift b/Sources/geometrize/ShapeResult.swift
index a5da152..11c6ff6 100644
--- a/Sources/geometrize/ShapeResult.swift
+++ b/Sources/geometrize/ShapeResult.swift
@@ -4,9 +4,9 @@ import Foundation
 public struct ShapeResult {
     public let score: Double
     public let color: Rgba
-    public let shape: any Shape
+    public let shape: Shape
 
-    public init(score: Double, color: Rgba, shape: any Shape) {
+    public init(score: Double, color: Rgba, shape: Shape) {
         self.score = score
         self.color = color
         self.shape = shape
diff --git a/Sources/geometrize/State.swift b/Sources/geometrize/State.swift
index 060bd71..8851ecd 100644
--- a/Sources/geometrize/State.swift
+++ b/Sources/geometrize/State.swift
@@ -2,7 +2,7 @@ import Foundation
 
 struct State: Sendable {
 
-    init(score: Double, alpha: UInt8, shape: some Shape) {
+    init(score: Double, alpha: UInt8, shape: Shape) {
         self.score = score
         self.alpha = alpha
         self.shape = shape
@@ -15,7 +15,7 @@ struct State: Sendable {
     let alpha: UInt8
 
     /// The geometric primitive owned by the state.
-    let shape: any Shape
+    let shape: Shape
 
     ///  Modifies the current state in a random fashion.
     /// - Returns: new mutated state.
@@ -23,7 +23,7 @@ struct State: Sendable {
         x xRange: ClosedRange<Int>, // TODO: rename
         y yRange: ClosedRange<Int>, // TODO: rename
         using generator: inout SplitMix64,
-        score: ((any Shape) -> Double)
+        score: ((Shape) -> Double)
     ) -> State {
         let mutatedShape = shape.mutate(x: xRange, y: yRange, using: &generator)
         return State(score: score(mutatedShape), alpha: alpha, shape: mutatedShape)
diff --git a/Tests/geometrizeTests/hillClimbTests.swift b/Tests/geometrizeTests/hillClimbTests.swift
index e2518c8..8e19459 100644
--- a/Tests/geometrizeTests/hillClimbTests.swift
+++ b/Tests/geometrizeTests/hillClimbTests.swift
@@ -79,7 +79,7 @@ final class HillClimbTests: XCTestCase {
 
 }
 
-func == (lhs: any Shape, rhs: any Shape) -> Bool {
+func == (lhs: Shape, rhs: Shape) -> Bool {
     switch (lhs, rhs) {
     case (let lhs as Circle, let rhs as Circle): return lhs == rhs
     case (let lhs as Ellipse, let rhs as Ellipse): return lhs == rhs