diff --git a/Sources/DoggieCore/Swift/CollectionExtension.swift b/Sources/DoggieCore/Swift/CollectionExtension.swift
index e530bf42..acbc1c4f 100644
--- a/Sources/DoggieCore/Swift/CollectionExtension.swift
+++ b/Sources/DoggieCore/Swift/CollectionExtension.swift
@@ -153,7 +153,7 @@ extension Sequence {
     }
 }
 
-extension Collection where SubSequence: Collection {
+extension Collection {
     
     @inlinable
     public func rotated(at index: Index) -> Chain2<SubSequence, SubSequence> {
@@ -161,7 +161,7 @@ extension Collection where SubSequence: Collection {
     }
 }
 
-extension Collection where SubSequence: Collection {
+extension Collection {
     
     @inlinable
     public func rotated(_ n: Int) -> Chain2<SubSequence, SubSequence> {
diff --git a/Sources/DoggieGeometry/ShapeRegion/PathBuilder.swift b/Sources/DoggieGeometry/ShapeRegion/PathBuilder.swift
index 8730e295..e52b9ef0 100644
--- a/Sources/DoggieGeometry/ShapeRegion/PathBuilder.swift
+++ b/Sources/DoggieGeometry/ShapeRegion/PathBuilder.swift
@@ -25,7 +25,7 @@
 
 private let ShapeCacheInterscetionResultKey = "ShapeCacheInterscetionResultKey"
 
-extension Collection where SubSequence: Collection {
+extension Collection {
     
     func rotateZip() -> Zip2Sequence<Self, Chain2<SubSequence, SubSequence>> {
         return zip(self, self.rotated(1))