diff --git a/Makefile b/Makefile
index 2e77296d8..9e22f55bf 100644
--- a/Makefile
+++ b/Makefile
@@ -108,7 +108,7 @@ format:
 	clang-format -i $(LIBRARY_SOURCES) $(DEMO_SOURCES) $(GLTFPACK_SOURCES)
 
 formatjs:
-	prettier -w js/*.js gltf/*.js demo/*.html
+	prettier -w js/*.js gltf/*.js demo/*.html js/*.ts
 
 js: js/meshopt_decoder.js js/meshopt_decoder.module.js js/meshopt_encoder.js js/meshopt_encoder.module.js js/meshopt_simplifier.js js/meshopt_simplifier.module.js
 
diff --git a/js/meshopt_decoder.module.d.ts b/js/meshopt_decoder.module.d.ts
index 8546a2f41..667dfb7be 100644
--- a/js/meshopt_decoder.module.d.ts
+++ b/js/meshopt_decoder.module.d.ts
@@ -1,15 +1,15 @@
 // This file is part of meshoptimizer library and is distributed under the terms of MIT License.
 // Copyright (C) 2016-2024, by Arseny Kapoulkine (arseny.kapoulkine@gmail.com)
 export const MeshoptDecoder: {
-    supported: boolean;
-    ready: Promise<void>;
-    
-    decodeVertexBuffer: (target: Uint8Array, count: number, size: number, source: Uint8Array, filter?: string) => void;
-    decodeIndexBuffer: (target: Uint8Array, count: number, size: number, source: Uint8Array) => void;
-    decodeIndexSequence: (target: Uint8Array, count: number, size: number, source: Uint8Array) => void;
+	supported: boolean;
+	ready: Promise<void>;
 
-    decodeGltfBuffer: (target: Uint8Array, count: number, size: number, source: Uint8Array, mode: string, filter?: string) => void;
+	decodeVertexBuffer: (target: Uint8Array, count: number, size: number, source: Uint8Array, filter?: string) => void;
+	decodeIndexBuffer: (target: Uint8Array, count: number, size: number, source: Uint8Array) => void;
+	decodeIndexSequence: (target: Uint8Array, count: number, size: number, source: Uint8Array) => void;
 
-    useWorkers: (count: number) => void;
-    decodeGltfBufferAsync: (count: number, size: number, source: Uint8Array, mode: string, filter?: string) => Promise<Uint8Array>;
+	decodeGltfBuffer: (target: Uint8Array, count: number, size: number, source: Uint8Array, mode: string, filter?: string) => void;
+
+	useWorkers: (count: number) => void;
+	decodeGltfBufferAsync: (count: number, size: number, source: Uint8Array, mode: string, filter?: string) => Promise<Uint8Array>;
 };
diff --git a/js/meshopt_encoder.module.d.ts b/js/meshopt_encoder.module.d.ts
index 4855326af..614fc0463 100644
--- a/js/meshopt_encoder.module.d.ts
+++ b/js/meshopt_encoder.module.d.ts
@@ -1,19 +1,19 @@
 // This file is part of meshoptimizer library and is distributed under the terms of MIT License.
 // Copyright (C) 2016-2024, by Arseny Kapoulkine (arseny.kapoulkine@gmail.com)
 export const MeshoptEncoder: {
-    supported: boolean;
-    ready: Promise<void>;
+	supported: boolean;
+	ready: Promise<void>;
 
-    reorderMesh: (indices: Uint32Array, triangles: boolean, optsize: boolean) => [Uint32Array, number];
-    reorderPoints: (positions: Float32Array, positions_stride: number) => Uint32Array;
-    
-    encodeVertexBuffer: (source: Uint8Array, count: number, size: number) => Uint8Array;
-    encodeIndexBuffer: (source: Uint8Array, count: number, size: number) => Uint8Array;
-    encodeIndexSequence: (source: Uint8Array, count: number, size: number) => Uint8Array;
+	reorderMesh: (indices: Uint32Array, triangles: boolean, optsize: boolean) => [Uint32Array, number];
+	reorderPoints: (positions: Float32Array, positions_stride: number) => Uint32Array;
 
-    encodeGltfBuffer: (source: Uint8Array, count: number, size: number, mode: string) => Uint8Array;
+	encodeVertexBuffer: (source: Uint8Array, count: number, size: number) => Uint8Array;
+	encodeIndexBuffer: (source: Uint8Array, count: number, size: number) => Uint8Array;
+	encodeIndexSequence: (source: Uint8Array, count: number, size: number) => Uint8Array;
 
-    encodeFilterOct: (source: Float32Array, count: number, stride: number, bits: number) => Uint8Array;
-    encodeFilterQuat: (source: Float32Array, count: number, stride: number, bits: number) => Uint8Array;
-    encodeFilterExp: (source: Float32Array, count: number, stride: number, bits: number, mode?: "Separate" | "SharedVector" | "SharedComponent") => Uint8Array;
+	encodeGltfBuffer: (source: Uint8Array, count: number, size: number, mode: string) => Uint8Array;
+
+	encodeFilterOct: (source: Float32Array, count: number, stride: number, bits: number) => Uint8Array;
+	encodeFilterQuat: (source: Float32Array, count: number, stride: number, bits: number) => Uint8Array;
+	encodeFilterExp: (source: Float32Array, count: number, stride: number, bits: number, mode?: 'Separate' | 'SharedVector' | 'SharedComponent') => Uint8Array;
 };
diff --git a/js/meshopt_simplifier.module.d.ts b/js/meshopt_simplifier.module.d.ts
index b0131756b..720900b65 100644
--- a/js/meshopt_simplifier.module.d.ts
+++ b/js/meshopt_simplifier.module.d.ts
@@ -1,22 +1,22 @@
 // This file is part of meshoptimizer library and is distributed under the terms of MIT License.
 // Copyright (C) 2016-2024, by Arseny Kapoulkine (arseny.kapoulkine@gmail.com)
-export type Flags = "LockBorder" | "Sparse" | "ErrorAbsolute";
+export type Flags = 'LockBorder' | 'Sparse' | 'ErrorAbsolute';
 
 export const MeshoptSimplifier: {
-    supported: boolean;
-    ready: Promise<void>;
+	supported: boolean;
+	ready: Promise<void>;
 
-    useExperimentalFeatures: boolean;
+	useExperimentalFeatures: boolean;
 
-    compactMesh: (indices: Uint32Array) => [Uint32Array, number];
+	compactMesh: (indices: Uint32Array) => [Uint32Array, number];
 
-    simplify: (indices: Uint32Array, vertex_positions: Float32Array, vertex_positions_stride: number, target_index_count: number, target_error: number, flags?: Flags[]) => [Uint32Array, number];
+	simplify: (indices: Uint32Array, vertex_positions: Float32Array, vertex_positions_stride: number, target_index_count: number, target_error: number, flags?: Flags[]) => [Uint32Array, number];
 
-    // Experimental; requires useExperimentalFeatures to be set to true
-    simplifyWithAttributes: (indices: Uint32Array, vertex_positions: Float32Array, vertex_positions_stride: number, vertex_attributes: Float32Array, vertex_attributes_stride: number, attribute_weights: number[], vertex_lock: boolean[] | null, target_index_count: number, target_error: number, flags?: Flags[]) => [Uint32Array, number];
+	// Experimental; requires useExperimentalFeatures to be set to true
+	simplifyWithAttributes: (indices: Uint32Array, vertex_positions: Float32Array, vertex_positions_stride: number, vertex_attributes: Float32Array, vertex_attributes_stride: number, attribute_weights: number[], vertex_lock: boolean[] | null, target_index_count: number, target_error: number, flags?: Flags[]) => [Uint32Array, number];
 
-    getScale: (vertex_positions: Float32Array, vertex_positions_stride: number) => number;
+	getScale: (vertex_positions: Float32Array, vertex_positions_stride: number) => number;
 
-    // Experimental; requires useExperimentalFeatures to be set to true
-    simplifyPoints: (vertex_positions: Float32Array, vertex_positions_stride: number, target_vertex_count: number, vertex_colors?: Float32Array, vertex_colors_stride?: number, color_weight?: number) => Uint32Array;
+	// Experimental; requires useExperimentalFeatures to be set to true
+	simplifyPoints: (vertex_positions: Float32Array, vertex_positions_stride: number, target_vertex_count: number, vertex_colors?: Float32Array, vertex_colors_stride?: number, color_weight?: number) => Uint32Array;
 };