diff --git a/CHANGELOG.md b/CHANGELOG.md
index 317cf30..f12bf22 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 All notable changes to this project will be documented in this file.
 
+## 0.6.2 - 2024-01-??
+
+- CLI: recommend additional installation on help
+
 ## 0.6.1 - 2024-01-14
 
 - Support setting record type(s)
diff --git a/bin/avram.js b/bin/avram.js
index d2f99e8..35faf14 100755
--- a/bin/avram.js
+++ b/bin/avram.js
@@ -1,8 +1,17 @@
 #!/usr/bin/env node
 import cli from "../lib/cli.js"
-import formats from "../lib/formats.js"
+import { formats, missing } from "../lib/formats.js"
 import avramAction from "../lib/action.js"
 
+console.log(missing)
+
+import ajv from "../lib/ajv.js"
+var details = ajv ? "" : `
+Install ajv and ajv-formats for better validation of schemas.`
+
+if (missing.size) details += `
+Install ${[...missing.keys()].join(", ")} for additional input formats.`
+
 cli.usage("avram [options] [validation options] <schema> [<files...>]")
   .description("Validate file(s) with an Avram schema")
   .option(`-f, --format [name]     input format (${Object.keys(formats).join("|")})`)
@@ -11,9 +20,7 @@ cli.usage("avram [options] [validation options] <schema> [<files...>]")
   .option("-p, --print             print all input records (in JSON)")
   .option("-v, --verbose           verbose error messages")
   .option("-l, --list              list supported validation options")
-  .details(`
-An empty string schema argument uses the empty schema. Combining -n and -v
-emits parsed records. See supported validation options with --list.`)
+  .details(details)
   .action(avramAction)
   .parse(process.argv)
   .catch(e => {
diff --git a/lib/action.js b/lib/action.js
index 59e6d55..6aed36d 100644
--- a/lib/action.js
+++ b/lib/action.js
@@ -3,7 +3,7 @@ import { Validator } from "./validate.js"
 import { SchemaValidator } from "./schema-validator.js"
 import { optionHelp, optionDefault } from "./options.js"
 import cli from "./cli.js"
-import formats from "../lib/formats.js"
+import { formats } from "../lib/formats.js"
 
 function loadSchema(file, opt) {
   const schema = JSON.parse(fs.readFileSync(file))
diff --git a/lib/ajv.js b/lib/ajv.js
new file mode 100644
index 0000000..ecaeb66
--- /dev/null
+++ b/lib/ajv.js
@@ -0,0 +1,15 @@
+import { createRequire } from "node:module"
+const require = createRequire(import.meta.url)
+
+const { default: Ajv } = await import("ajv").catch(() => ({}))
+const { default: addFormats } = await import("ajv-formats").catch(() => ({}))
+
+// export initialized ajv, if available
+export default (() => { 
+  if (Ajv && addFormats) {
+    const ajv = new Ajv({strictTypes: false})
+    addFormats(ajv)
+    ajv.addMetaSchema(require("ajv/lib/refs/json-schema-draft-06.json"))
+    return ajv
+  }
+})()
diff --git a/lib/formats.js b/lib/formats.js
index e093bfd..4bfb032 100644
--- a/lib/formats.js
+++ b/lib/formats.js
@@ -1,5 +1,4 @@
 import { Transform } from "stream"
-
 import { Record } from "./record.js"
 
 const recordTransform = mapping => new Transform({
@@ -14,7 +13,7 @@ const marcTransform = recordTransform(Record.fromMarcjs)
 const picaTransform = recordTransform(Record.fromPicajson)
 const flatTransform = recordTransform(Record.fromObject)
 
-const formats = {}
+export const formats = {}
 
 const plugins = {
   marcjs: module => {
@@ -49,15 +48,17 @@ const plugins = {
   // TODO: add split2 to support, tsv... ndjson...
 }
 
+export const missing = new Set(Object.keys(plugins))
+
 // dynamically load optional modules in parallel
 const modules = Object.keys(plugins)
 await Promise.allSettled(modules.map(m => import(m)))
   .then(imports => {
     imports.forEach(({value}, i) => {
       if (value) {
-        plugins[modules[i]](value)
+        const module = modules[i]
+        plugins[module](value)
+        missing.delete(module)
       }
     })
   })
-
-export default formats
diff --git a/lib/schema-validator.js b/lib/schema-validator.js
index ac826c3..67224dd 100644
--- a/lib/schema-validator.js
+++ b/lib/schema-validator.js
@@ -1,14 +1,8 @@
-import { readFileSync } from "fs"
+import ajv from "./ajv.js"
 
+import { readFileSync } from "fs"
 const jsonSchema = JSON.parse(readFileSync(new URL("../avram-schema.json", import.meta.url)))
 
-// load ajv, if available
-import { createRequire } from "node:module"
-const require = createRequire(import.meta.url)
-
-const { default: Ajv } = await import("ajv").catch(() => ({}))
-const { default: addFormats } = await import("ajv-formats").catch(() => ({}))
-
 const families = {
   flat: { id: /./, disallow: ["occurrence", "counter", "indicator1", "indicator2", "subfields"] },
   marc: { id: /^([0-9]{3}|LDR)$/, disallow: ["occurrence", "counter"] },
@@ -18,10 +12,7 @@ const families = {
 
 export class SchemaValidator {
   constructor() {
-    if (Ajv && addFormats) {
-      const ajv = new Ajv({strictTypes: false})
-      ajv.addMetaSchema(require("ajv/lib/refs/json-schema-draft-06.json"))
-      addFormats(ajv)
+    if (ajv) {
       this.validator = ajv.compile(jsonSchema)
     } else {
       console.warn("ajv and/or ajv-formats is not installed so Avram schema validation is very limited!")