diff --git a/node/scripts/generate-constants.js b/node/scripts/generate-constants.js
index 6f7c25935..7e821dc0a 100755
--- a/node/scripts/generate-constants.js
+++ b/node/scripts/generate-constants.js
@@ -1,69 +1,65 @@
 #!/usr/bin/env node
-const fs = require('fs/promises')
+const fs = require('fs')
 const path = require('path')
 
 const data = []
-const regex = /^#define\s+(\w+)\s+(\w+)/i
 const header = path.resolve(__dirname, '../../deltachat-ffi/deltachat.h')
 
-;(async () => {
-  console.log('Generating constants...')
-  const header_data = await fs.readFile(header, 'utf-8')
-  for (const line of header_data.split(/\r?\n/g)) {
-    const match = regex.exec(line)
-    if (match) {
-      const key = match[1]
-      const value = parseInt(match[2])
-      if (isNaN(value)) continue
+console.log('Generating constants...')
 
-      data.push({ key, value })
-    }
+const header_data = fs.readFileSync(header, 'UTF-8')
+const regex = /^#define\s+(\w+)\s+(\w+)/gm
+while (null != (match = regex.exec(header_data))) {
+  const key = match[1]
+  const value = parseInt(match[2])
+  if (!isNaN(value)) {
+    data.push({ key, value })
   }
+}
 
-  delete header_data
+delete header_data
 
-  const constants = data
-    .filter(
-      ({ key }) => key.toUpperCase()[0] === key[0] // check if define name is uppercase
-    )
-    .sort((lhs, rhs) => {
-      if (lhs.key < rhs.key) return -1
-      else if (lhs.key > rhs.key) return 1
-      return 0
-    })
-    .map((row) => {
-      return `  ${row.key}: ${row.value}`
-    })
-    .join(',\n')
-
-  const events = data
-    .sort((lhs, rhs) => {
-      if (lhs.value < rhs.value) return -1
-      else if (lhs.value > rhs.value) return 1
-      return 0
-    })
-    .filter((i) => {
-      return i.key.startsWith('DC_EVENT_')
-    })
-    .map((i) => {
-      return `  ${i.value}: '${i.key}'`
-    })
-    .join(',\n')
-
-  // backwards compat
-  await fs.writeFile(
-    path.resolve(__dirname, '../constants.js'),
-    `// Generated!\n\nmodule.exports = {\n${constants}\n}\n`
-  )
-  // backwards compat
-  await fs.writeFile(
-    path.resolve(__dirname, '../events.js'),
-    `/* eslint-disable quotes */\n// Generated!\n\nmodule.exports = {\n${events}\n}\n`
+const constants = data
+  .filter(
+    ({ key }) => key.toUpperCase()[0] === key[0] // check if define name is uppercase
   )
+  .sort((lhs, rhs) => {
+    if (lhs.key < rhs.key) return -1
+    else if (lhs.key > rhs.key) return 1
+    return 0
+  })
+  .map((row) => {
+    return `  ${row.key}: ${row.value}`
+  })
+  .join(',\n')
 
-  await fs.writeFile(
-    path.resolve(__dirname, '../lib/constants.ts'),
-    `// Generated!\n\nexport enum C {\n${constants.replace(/:/g, ' =')},\n}\n
+const events = data
+  .sort((lhs, rhs) => {
+    if (lhs.value < rhs.value) return -1
+    else if (lhs.value > rhs.value) return 1
+    return 0
+  })
+  .filter((i) => {
+    return i.key.startsWith('DC_EVENT_')
+  })
+  .map((i) => {
+    return `  ${i.value}: '${i.key}'`
+  })
+  .join(',\n')
+
+// backwards compat
+fs.writeFileSync(
+  path.resolve(__dirname, '../constants.js'),
+  `// Generated!\n\nmodule.exports = {\n${constants}\n}\n`
+)
+// backwards compat
+fs.writeFileSync(
+  path.resolve(__dirname, '../events.js'),
+  `/* eslint-disable quotes */\n// Generated!\n\nmodule.exports = {\n${events}\n}\n`
+)
+
+fs.writeFileSync(
+  path.resolve(__dirname, '../lib/constants.ts'),
+  `// Generated!\n\nexport enum C {\n${constants.replace(/:/g, ' =')},\n}\n
 // Generated!\n\nexport const EventId2EventName: { [key: number]: string } = {\n${events},\n}\n`
-  )
-})()
+)