diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4161114..73ed1ab 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -53,3 +53,4 @@ First stable release.
 
 - When local server is installed but not running, Gramma will now try to use command-line interface for LanguageTool communication instead of spawning HTTP server (if possible).
 - Gramma will now automatically check for updates once a day.
+- Added validation for languages and rules parameters.
diff --git a/src/cli.js b/src/cli.js
index ad7f1c9..1e4de2b 100755
--- a/src/cli.js
+++ b/src/cli.js
@@ -15,6 +15,9 @@ const paths = require("./commands/paths")
 const server = require("./commands/server")
 const { hook } = require("./commands/hook")
 
+const { languageOptions } = require("./validators/languages")
+const { ruleOptions } = require("./validators/rules")
+
 // eslint-disable-next-line no-unused-expressions
 yargs
   .command(
@@ -109,18 +112,21 @@ yargs
     type: "string",
     default: "config",
     describe: "Set the language of the text",
+    choices: languageOptions,
   })
   .option("disable", {
     alias: "d",
     type: "string",
     describe: "Disable specific rule",
     default: [],
+    choices: ruleOptions,
   })
   .option("enable", {
     alias: "e",
     type: "string",
     describe: "Enable specific rule",
     default: [],
+    choices: ruleOptions,
   })
   .option("all", {
     alias: "a",
diff --git a/src/requests/checkViaCmd.js b/src/requests/checkViaCmd.js
index a71e9f3..747f5d5 100644
--- a/src/requests/checkViaCmd.js
+++ b/src/requests/checkViaCmd.js
@@ -1,5 +1,6 @@
 const fs = require("fs")
 const path = require("path")
+const kleur = require("kleur")
 const { execSync } = require("child_process")
 const initialConfig = require("../initialConfig")
 
@@ -44,7 +45,12 @@ const MAX_REPLACEMENTS = 30
  *
  * @returns {Promise<Object>} grammar checker suggestions
  */
-const checkViaCmd = (text, options = {}, serverDirPath, configDirPath) => {
+const checkViaCmd = async (
+  text,
+  options = {},
+  serverDirPath,
+  configDirPath,
+) => {
   const cfg = { ...initialConfig, ...options }
   // console.log({ cfg, serverDirPath, configDirPath })
 
@@ -65,19 +71,22 @@ const checkViaCmd = (text, options = {}, serverDirPath, configDirPath) => {
   const cmd = `java -jar ${jar}${lang}${disabled} --json ${tempFile}`
 
   let response
+  let result
 
   try {
     response = execSync(cmd, { stdio: "pipe" })
-    response = response.toString()
+    response = response.toString().split("\n")
+    result = JSON.parse(response[response.length - 1])
   } catch (e) {
     removeTempFile(tempFile)
-    throw new Error("Cannot execute command via local LanguageTool cmd")
+
+    console.log(kleur.red("Cannot execute command via local LanguageTool cmd"))
+    console.log("Please check if your command if valid.")
+    process.exit(1)
   }
 
   removeTempFile(tempFile)
 
-  const result = JSON.parse(response)
-
   const resultWithWords = {
     ...result,
     matches: removeFalsePositives(
diff --git a/src/requests/checkWithFallback.js b/src/requests/checkWithFallback.js
index 89bc665..b4170ad 100644
--- a/src/requests/checkWithFallback.js
+++ b/src/requests/checkWithFallback.js
@@ -25,7 +25,7 @@ const checkWithFallback = async (text, cfg) => {
         if (!session.markdown) {
           console.info(`Checking via local LanguageTool cmd...`)
 
-          response = checkViaCmd(
+          response = await checkViaCmd(
             text,
             session,
             global.server_path,