diff --git a/types/sat/index.d.ts b/types/sat/index.d.ts
index 008f65d7b5..538228049c 100644
--- a/types/sat/index.d.ts
+++ b/types/sat/index.d.ts
@@ -14,7 +14,7 @@ declare namespace SAT {
 		 * @param {number} x The x-coordinate of the Vector.
 		 * @param {number} y The y-coordinate of the Vector.
 		 */
-		constructor(x: number, y: number);
+		constructor(x?: number, y?: number);
 
 		x: number;
 		y: number;
@@ -27,7 +27,7 @@ declare namespace SAT {
 		normalize(): Vector;
 		add(other: Vector): Vector;
 		sub(other: Vector): Vector;
-		scale(x: number, y: number): Vector;
+		scale(x: number, y?: number): Vector;
 		project(other: Vector): Vector;
 		projectN(other: Vector): Vector;
 		reflect(axis: Vector): Vector;
@@ -40,13 +40,13 @@ declare namespace SAT {
 	 * This is simple circle with a center {pos} position and radius {r}.
 	 */
 	export class Circle {
-		constructor(pos: Vector, r: number);
+		constructor(pos?: Vector, r?: number);
 
 		pos: Vector;
 		r: number;
 	}
 	export class Polygon {
-		constructor(pos: Vector, points: Vector[]);
+		constructor(pos?: Vector, points?: Vector[]);
 
 		pos: Vector;
 		points: Vector[];
@@ -66,7 +66,7 @@ declare namespace SAT {
 
 	}
 	export class Box {
-		constructor(pos: Vector, width: number, height: number);
+		constructor(pos?: Vector, width?: number, height?: number);
 
 		pos: Vector;
 		w: number;
diff --git a/types/sat/tsconfig.json b/types/sat/tsconfig.json
index f9b3aa2f9c..75c7dbc256 100644
--- a/types/sat/tsconfig.json
+++ b/types/sat/tsconfig.json
@@ -7,7 +7,7 @@
         ],
         "noImplicitAny": true,
         "noImplicitThis": true,
-        "strictNullChecks": false,
+        "strictNullChecks": true,
         "strictFunctionTypes": true,
         "baseUrl": "../",
         "typeRoots": [
@@ -21,4 +21,4 @@
         "index.d.ts",
         "sat-tests.ts"
     ]
-}
\ No newline at end of file
+}