diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 3db3def5..9d6eefd5 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -40,9 +40,14 @@ importers:
       spritesmith: ^3.4.0
   tools/trim:
     dependencies:
+      '@types/node': 14.0.23
       commander: 5.1.0
+    devDependencies:
+      typescript: 3.9.7
     specifiers:
+      '@types/node': ^14.0.23
       commander: ^5.1.0
+      typescript: ^3.9.7
   tools/tupctime:
     dependencies:
       better-sqlite3: 7.0.1
diff --git a/tools/trim/image.js b/tools/trim/image.ts
similarity index 74%
rename from tools/trim/image.js
rename to tools/trim/image.ts
index 372634dd..edf8ae4d 100644
--- a/tools/trim/image.js
+++ b/tools/trim/image.ts
@@ -1,7 +1,7 @@
 
 import cp from 'child_process';
 
-export function getDims(input) {
+export function getDims(input : string) {
     const info = cp.execFileSync('convert', [input, '-format', "%w+%h+%@", 'info:'],
                                  {encoding:'utf8'});
 
@@ -21,13 +21,13 @@ export function getDims(input) {
     }
 }
 
-export function crop(input, {width, height, left, top}, output) {
+export function crop(input : string, {width, height, left, top} : {width : number, height: number, left: number, top: number}, output : string) {
     cp.execFileSync('convert', [input, '+repage', '-crop', `${width}x${height}+${left}+${top}`, output]);
 }
 
 // Trim, preserving displacement from center
 // Returns crop coords
-export function losslessTrim(dims) {
+export function losslessTrim(dims : {width : number, height: number, left: number, top: number, bottom: number, right: number}) {
     return {
         left: Math.min(dims.left, dims.right),
         width: dims.width + Math.abs(dims.left - dims.right),
diff --git a/tools/trim/index.js b/tools/trim/index.ts
similarity index 100%
rename from tools/trim/index.js
rename to tools/trim/index.ts
diff --git a/tools/trim/package.json b/tools/trim/package.json
index c47d6951..389f6bdf 100644
--- a/tools/trim/package.json
+++ b/tools/trim/package.json
@@ -1,6 +1,14 @@
 {
     "dependencies": {
+        "@types/node": "^14.0.23",
         "commander": "^5.1.0"
     },
-    "type": "module"
+    "type": "module",
+    "main": "./dist/index.js",
+    "scripts": {
+        "prepare": "tsc"
+    },
+    "devDependencies": {
+        "typescript": "^3.9.7"
+    }
 }
diff --git a/tools/trim/tsconfig.json b/tools/trim/tsconfig.json
new file mode 100644
index 00000000..cded0362
--- /dev/null
+++ b/tools/trim/tsconfig.json
@@ -0,0 +1,7 @@
+{
+    "extends": "../../tsconfig-base",
+    "compilerOptions": {
+        "outDir": "dist",
+        "allowJs": true
+    }
+}