diff --git a/Sources/GeoJSON/GeoJSON+Codable.swift b/Sources/GeoJSON/GeoJSON+Codable.swift
index 4a79b1d..e388457 100644
--- a/Sources/GeoJSON/GeoJSON+Codable.swift
+++ b/Sources/GeoJSON/GeoJSON+Codable.swift
@@ -145,7 +145,7 @@ extension LinearRingCoordinates {
 
 fileprivate enum SingleGeometryCodingKeys: String, CodingKey {
 	case geoJSONType = "type"
-	case coordinates
+	case coordinates, bbox
 }
 
 extension SingleGeometry {
@@ -171,6 +171,7 @@ extension SingleGeometry {
 		
 		try container.encode(Self.geoJSONType, forKey: .geoJSONType)
 		try container.encode(self.coordinates, forKey: .coordinates)
+		try container.encode(self.bbox, forKey: .bbox)
 	}
 	
 }
diff --git a/Sources/GeoJSON/Helpers/GeoJSON+Boundable.swift b/Sources/GeoJSON/Helpers/GeoJSON+Boundable.swift
index 5f24725..3cc1e05 100644
--- a/Sources/GeoJSON/Helpers/GeoJSON+Boundable.swift
+++ b/Sources/GeoJSON/Helpers/GeoJSON+Boundable.swift
@@ -12,7 +12,7 @@ import Turf
 extension NonEmpty: Boundable where Collection: Hashable, Element: Boundable {
 	
 	public var _bbox: Element.BoundingBox {
-		self.reduce(.zero, { $0.union($1.bbox) })
+		self.reduce(nil, { $0.union($1.bbox) }) ?? .zero
 	}
 	
 }
diff --git a/Sources/GeoModels/BoundingBox.swift b/Sources/GeoModels/BoundingBox.swift
index c4b815d..7d51e48 100644
--- a/Sources/GeoModels/BoundingBox.swift
+++ b/Sources/GeoModels/BoundingBox.swift
@@ -13,3 +13,11 @@ public protocol BoundingBox: Hashable {
 	func union(_ other: Self) -> Self
 	
 }
+
+extension Optional where Wrapped: BoundingBox {
+	
+	public func union(_ bbox: Wrapped) -> Wrapped {
+		self?.union(bbox) ?? bbox
+	}
+	
+}
diff --git a/Sources/Turf/Boundable.swift b/Sources/Turf/Boundable.swift
index 3bb48cc..1e8343d 100644
--- a/Sources/Turf/Boundable.swift
+++ b/Sources/Turf/Boundable.swift
@@ -76,7 +76,7 @@ extension BoundingBox3D: Boundable {
 //extension Collection: Boundable where Element: Boundable {
 //
 //	public var _bbox: Element.BoundingBox {
-//		self.reduce(.zero, { $0.union($1.bbox) })
+//		self.reduce(nil, { $0.union($1.bbox) }) ?? .zero
 //	}
 //
 //}
@@ -84,7 +84,7 @@ extension BoundingBox3D: Boundable {
 extension Array: Boundable where Element: Boundable {
 	
 	public var _bbox: Element.BoundingBox {
-		self.reduce(.zero, { $0.union($1.bbox) })
+		self.reduce(nil, { $0.union($1.bbox) }) ?? .zero
 	}
 	
 }
@@ -92,7 +92,7 @@ extension Array: Boundable where Element: Boundable {
 extension Set: Boundable where Element: Boundable {
 	
 	public var _bbox: Element.BoundingBox {
-		self.reduce(.zero, { $0.union($1.bbox) })
+		self.reduce(nil, { $0.union($1.bbox) }) ?? .zero
 	}
 	
 }
diff --git a/Sources/Turf/Turf.swift b/Sources/Turf/Turf.swift
index 628bdd2..68d10af 100644
--- a/Sources/Turf/Turf.swift
+++ b/Sources/Turf/Turf.swift
@@ -68,7 +68,7 @@ public func bbox<C: Collection>(for coords: C) -> BoundingBox3D? where C.Element
 public func bbox<T: Boundable, C: Collection>(for boundables: C) -> T.BoundingBox? where C.Element == T {
 	guard !boundables.isEmpty else { return nil }
 	
-	return boundables.reduce(.zero, { $0.union($1.bbox) })
+	return boundables.reduce(nil, { $0.union($1.bbox) }) ?? .zero
 }
 
 /// Returns the absolute center of a polygon.
diff --git a/Tests/GeoJSONTests/GeoJSON+EncodableTests.swift b/Tests/GeoJSONTests/GeoJSON+EncodableTests.swift
index 349ca49..66522eb 100644
--- a/Tests/GeoJSONTests/GeoJSON+EncodableTests.swift
+++ b/Tests/GeoJSONTests/GeoJSON+EncodableTests.swift
@@ -26,7 +26,8 @@ final class GeoJSONEncodableTests: XCTestCase {
 		XCTAssertEqual(string, [
 			"{",
 				"\"type\":\"Point\",",
-				"\"coordinates\":[-1.55366,47.21881]",
+				"\"coordinates\":[-1.55366,47.21881],",
+				"\"bbox\":[-1.55366,47.21881,-1.55366,47.21881]",
 			"}",
 		].joined())
 	}
@@ -41,7 +42,8 @@ final class GeoJSONEncodableTests: XCTestCase {
 				"\"type\":\"MultiPoint\",",
 				"\"coordinates\":[",
 					"[-1.55366,47.21881]",
-				"]",
+				"],",
+				"\"bbox\":[-1.55366,47.21881,-1.55366,47.21881]",
 			"}",
 		].joined())
 	}
@@ -57,7 +59,8 @@ final class GeoJSONEncodableTests: XCTestCase {
 				"\"coordinates\":[",
 					"[-1.55366,47.21881],",
 					"[2.3529,48.85719]",
-				"]",
+				"],",
+				"\"bbox\":[-1.55366,47.21881,2.3529,48.85719]",
 			"}",
 		].joined())
 	}
@@ -79,7 +82,8 @@ final class GeoJSONEncodableTests: XCTestCase {
 						"[2.3529,48.85719],",
 						"[5.36468,43.29868]",
 					"]",
-				"]",
+				"],",
+				"\"bbox\":[-1.55366,43.29868,5.36468,48.85719]",
 			"}",
 		].joined())
 	}
@@ -102,7 +106,8 @@ final class GeoJSONEncodableTests: XCTestCase {
 						"[2.3529,48.85719],",
 						"[-1.55366,47.21881]",
 					"]",
-				"]",
+				"],",
+				"\"bbox\":[-1.55366,43.29868,5.36468,48.85719]",
 			"}",
 		].joined())
 	}
@@ -133,7 +138,8 @@ final class GeoJSONEncodableTests: XCTestCase {
 							"[-1.55366,47.21881]",
 						"]",
 					"]",
-				"]",
+				"],",
+				"\"bbox\":[-1.55366,43.29868,5.36468,48.85719]",
 			"}",
 		].joined())
 	}
@@ -155,7 +161,8 @@ final class GeoJSONEncodableTests: XCTestCase {
 				"\"type\":\"Feature\",",
 				"\"geometry\":{",
 					"\"type\":\"Point\",",
-					"\"coordinates\":[-1.55366,47.21881]",
+					"\"coordinates\":[-1.55366,47.21881],",
+					"\"bbox\":[-1.55366,47.21881,-1.55366,47.21881]",
 				"},",
 				"\"bbox\":[-1.55366,47.21881,-1.55366,47.21881]",
 			"}",
@@ -183,7 +190,8 @@ final class GeoJSONEncodableTests: XCTestCase {
 				"\"type\":\"Feature\",",
 				"\"geometry\":{",
 					"\"type\":\"Point\",",
-					"\"coordinates\":[-1.55366,47.21881]",
+					"\"coordinates\":[-1.55366,47.21881],",
+					"\"bbox\":[-1.55366,47.21881,-1.55366,47.21881]",
 				"},",
 				"\"bbox\":[-1.55366,47.21881,-1.55366,47.21881]",
 			"}",