diff --git a/README.md b/README.md
index 5a45fed..b7b3fef 100644
--- a/README.md
+++ b/README.md
@@ -57,17 +57,18 @@ To use a custom env filename or path, pass the `-f` flag. This is a major breaki
 Usage: env-cmd [options] -- <command> [...args]
 
 Options:
-  -v, --version                       output the version number
-  -e, --environments [env1,env2,...]  The rc file environment(s) to use
-  -f, --file [path]                   Custom env file path (default path: ./.env)
-  -x, --expand-envs                   Replace $var and ${var} in args and command with environment variables
-  --fallback                          Fallback to default env file path, if custom env file path not found
-  --no-override                       Do not override existing environment variables
-  --silent                            Ignore any env-cmd errors and only fail on executed program failure.
-  --use-shell                         Execute the command in a new shell with the given environment
-  --verbose                           Print helpful debugging information
-  --recursive                         Replace $var and ${var} in env file with the referenced environment variable
-  -h, --help                          output usage information
+  -v, --version                 output the version number
+  -e, --environments [envs...]  The rc file environment(s) to use
+  -f, --file [path]             Custom env file path or .rc file path if '-e' used (default path: ./.env or ./.env-cmdrc.(js|cjs|mjs|json))
+  -x, --expand-envs             Replace $var and ${var} in args and command with environment variables
+  --recursive                   Replace $var and ${var} in env file with the referenced environment variable
+  --fallback                    Fallback to default env file path, if custom env file path not found
+  --no-override                 Do not override existing environment variables
+  --silent                      Ignore any env-cmd errors and only fail on executed program failure.
+  --use-shell                   Execute the command in a new shell with the given environment
+  --verbose                     Print helpful debugging information
+  -h, --help                    display help for command
+
 ```
 
 ## 🔬 Advanced Usage
diff --git a/dist/expand-envs.d.ts b/dist/expand-envs.d.ts
index 420523e..c77ac26 100644
--- a/dist/expand-envs.d.ts
+++ b/dist/expand-envs.d.ts
@@ -1,6 +1,6 @@
 import type { Environment } from './types.ts';
 /**
  * expandEnvs Replaces $var and ${var} in args and command with environment variables
- * the environment variable doesn't exist, it leaves it as is.
+ * if the environment variable doesn't exist, it leaves it as is.
 */
 export declare function expandEnvs(str: string, envs: Environment): string;
diff --git a/dist/expand-envs.js b/dist/expand-envs.js
index a46c937..7fb5fd5 100644
--- a/dist/expand-envs.js
+++ b/dist/expand-envs.js
@@ -1,9 +1,9 @@
 /**
  * expandEnvs Replaces $var and ${var} in args and command with environment variables
- * the environment variable doesn't exist, it leaves it as is.
+ * if the environment variable doesn't exist, it leaves it as is.
 */
 export function expandEnvs(str, envs) {
-    return str.replace(/(?<!\\)\$\{?[a-zA-Z0-9_]+\}?/g, (varName) => {
+    return str.replace(/(?<!\\)\$(\{\w+\}|\w+)?/g, (varName) => {
         const varValue = envs[varName.startsWith('${') ? varName.slice(2, varName.length - 1) : varName.slice(1)];
         return varValue ?? varName;
     });
diff --git a/dist/parse-args.js b/dist/parse-args.js
index 5d51ec7..58a5ed9 100644
--- a/dist/parse-args.js
+++ b/dist/parse-args.js
@@ -88,18 +88,17 @@ export function parseArgsUsingCommander(args) {
         .usage('[options] -- <command> [...args]')
         .option('-e, --environments [envs...]', 'The rc file environment(s) to use', parseArgList)
         .option('-f, --file [path]', 'Custom env file path or .rc file path if \'-e\' used (default path: ./.env or ./.env-cmdrc.(js|cjs|mjs|json))')
-        .option('-x, --expand-envs', 'Replace $var and $\\{var\\} in args and command with environment variables')
+        .option('-x, --expand-envs', 'Replace $var and ${var} in args and command with environment variables')
+        .option('--recursive', 'Replace $var and ${var} in env file with the referenced environment variable')
         .option('--fallback', 'Fallback to default env file path, if custom env file path not found')
         .option('--no-override', 'Do not override existing environment variables')
         .option('--silent', 'Ignore any env-cmd errors and only fail on executed program failure.')
         .option('--use-shell', 'Execute the command in a new shell with the given environment')
         .option('--verbose', 'Print helpful debugging information')
-        .option('--recursive', 'Replace $var and $\\{var\\} in env file with the referenced environment variable')
         // TODO: Remove -r deprecation error on version >= v12
         .addOption(new Option('-r, --rc-file [path]', 'Deprecated Option')
         .hideHelp()
         .argParser(() => { throw new CommanderError(1, 'deprecated-option', 'The -r flag has been deprecated, use the -f flag instead.'); }))
-        // ENDTODO
         .allowUnknownOption(true)
         .allowExcessArguments(true)
         .parse(['_', '_', ...args], { from: 'node' });
diff --git a/src/expand-envs.ts b/src/expand-envs.ts
index 565665b..958405d 100644
--- a/src/expand-envs.ts
+++ b/src/expand-envs.ts
@@ -2,10 +2,10 @@ import type { Environment } from './types.ts'
 
 /**
  * expandEnvs Replaces $var and ${var} in args and command with environment variables
- * the environment variable doesn't exist, it leaves it as is.
+ * if the environment variable doesn't exist, it leaves it as is.
 */
 export function expandEnvs (str: string, envs: Environment): string {
-  return str.replace(/(?<!\\)\$\{?[a-zA-Z0-9_]+\}?/g, (varName) => {
+  return str.replace(/(?<!\\)\$(\{\w+\}|\w+)?/g, (varName) => {
     const varValue = envs[varName.startsWith('${') ? varName.slice(2, varName.length - 1) : varName.slice(1)]
     return varValue ?? varName
   })
diff --git a/src/parse-args.ts b/src/parse-args.ts
index de4adcf..03bdb25 100644
--- a/src/parse-args.ts
+++ b/src/parse-args.ts
@@ -100,8 +100,8 @@ export function parseArgsUsingCommander(args: string[]): CommanderOptions {
     .usage('[options] -- <command> [...args]')
     .option('-e, --environments [envs...]', 'The rc file environment(s) to use', parseArgList)
     .option('-f, --file [path]', 'Custom env file path or .rc file path if \'-e\' used (default path: ./.env or ./.env-cmdrc.(js|cjs|mjs|json))')
-    .option('-x, --expand-envs', 'Replace $var in args and command with environment variables')
-    .option('--recursive', 'Replace $var and $\\{var\\} in env file with the referenced environment variable')
+    .option('-x, --expand-envs', 'Replace $var and ${var} in args and command with environment variables')
+    .option('--recursive', 'Replace $var and ${var} in env file with the referenced environment variable')
     .option('--fallback', 'Fallback to default env file path, if custom env file path not found')
     .option('--no-override', 'Do not override existing environment variables')
     .option('--silent', 'Ignore any env-cmd errors and only fail on executed program failure.')
diff --git a/test/expand-envs.spec.ts b/test/expand-envs.spec.ts
index 1438de6..ca348e8 100644
--- a/test/expand-envs.spec.ts
+++ b/test/expand-envs.spec.ts
@@ -15,12 +15,14 @@ describe('expandEnvs', (): void => {
   const args = [
     'notvar', '$dollar', '\\$notvar', '-4', 
     '$PING', '$IP1', '\\$IP1', '$NONEXIST', 
-    '${PING}', '${NONEXIST}'
+    '${PING}', '${NONEXIST}', '\\${PING}', 
+    '$PING}', '${PING2'
   ]
   const argsExpanded = [
     'notvar', 'money', '\\$notvar', '-4', 
     'PONG', '127.0.0.1', '\\$IP1', '$NONEXIST', 
-    'PONG', '${NONEXIST}'
+    'PONG', '${NONEXIST}', '\\${PING}',
+    'PONG}', '${PING2'
   ]
 
   it('should replace environment variables in args', (): void => {