diff --git a/src/types.d.ts b/src/types.d.ts
index 12734450..58237b88 100644
--- a/src/types.d.ts
+++ b/src/types.d.ts
@@ -1,22 +1,27 @@
+interface IndexedCollection extends Iterable<number> {
+    readonly length: number;
+    [index: number]: number;
+}
+
 // prettier-ignore
 declare type mat2 =
   | [number, number, 
      number, number]
-  | Float32Array;
+  | IndexedCollection;
 
 // prettier-ignore
 declare type mat2d =
   | [number, number, 
      number, number, 
      number, number]
-  | Float32Array;
+  | IndexedCollection;
 
 // prettier-ignore
 declare type mat3 =
   | [number, number, number, 
      number, number, number, 
      number, number, number]
-  | Float32Array;
+  | IndexedCollection;
 
 // prettier-ignore
 declare type mat4 =
@@ -24,19 +29,19 @@ declare type mat4 =
      number, number, number, number,
      number, number, number, number,
      number, number, number, number]
-  | Float32Array;
+  | IndexedCollection;
 
-declare type quat = [number, number, number, number] | Float32Array;
+declare type quat = [number, number, number, number] | IndexedCollection;
 
 // prettier-ignore
 declare type quat2 =
   | [number, number, number, number, 
     number, number, number, number]
-  | Float32Array;
+  | IndexedCollection;
 
-declare type vec2 = [number, number] | Float32Array;
-declare type vec3 = [number, number, number] | Float32Array;
-declare type vec4 = [number, number, number, number] | Float32Array;
+declare type vec2 = [number, number] | IndexedCollection;
+declare type vec3 = [number, number, number] | IndexedCollection;
+declare type vec4 = [number, number, number, number] | IndexedCollection;
 
 // prettier-ignore
 declare type ReadonlyMat2 =
@@ -44,7 +49,7 @@ declare type ReadonlyMat2 =
       number, number,
       number, number
     ]
-  | Float32Array;
+  | IndexedCollection;
 
 // prettier-ignore
 declare type ReadonlyMat2d =
@@ -53,7 +58,7 @@ declare type ReadonlyMat2d =
       number, number,
       number, number
     ]
-  | Float32Array;
+  | IndexedCollection;
 
 // prettier-ignore
 declare type ReadonlyMat3 =
@@ -62,7 +67,7 @@ declare type ReadonlyMat3 =
       number, number, number,
       number, number, number
     ]
-  | Float32Array;
+  | IndexedCollection;
 
 // prettier-ignore
 declare type ReadonlyMat4 =
@@ -72,18 +77,18 @@ declare type ReadonlyMat4 =
       number, number, number, number,
       number, number, number, number
     ]
-  | Float32Array;
+  | IndexedCollection;
 
 declare type ReadonlyQuat =
   | readonly [number, number, number, number]
-  | Float32Array;
+  | IndexedCollection;
 
 declare type ReadonlyQuat2 =
   | readonly [number, number, number, number, number, number, number, number]
-  | Float32Array;
+  | IndexedCollection;
 
-declare type ReadonlyVec2 = readonly [number, number] | Float32Array;
-declare type ReadonlyVec3 = readonly [number, number, number] | Float32Array;
+declare type ReadonlyVec2 = readonly [number, number] | IndexedCollection;
+declare type ReadonlyVec3 = readonly [number, number, number] | IndexedCollection;
 declare type ReadonlyVec4 =
   | readonly [number, number, number, number]
-  | Float32Array;
+  | IndexedCollection;