diff --git a/src/Composer/Util/Hg.php b/src/Composer/Util/Hg.php
index 0e9f6e58f..c687542e0 100644
--- a/src/Composer/Util/Hg.php
+++ b/src/Composer/Util/Hg.php
@@ -58,10 +58,20 @@ class Hg
         }
 
         // Try with the authentication information available
-        if (Preg::isMatch('{^(https?)://((.+)(?:\:(.+))?@)?([^/]+)(/.*)?}mi', $url, $match) && $this->io->hasAuthentication((string) $match[5])) {
-            $auth = $this->io->getAuthentication((string) $match[5]);
-            $authenticatedUrl = $match[1] . '://' . rawurlencode($auth['username']) . ':' . rawurlencode($auth['password']) . '@' . $match[5] . $match[6];
-
+        if (
+            Preg::isMatch('{^(?P<proto>ssh|https?)://(?:(?P<user>[^:@]+)(?::(?P<pass>[^:@]+))?@)?(?P<host>[^/]+)(?P<path>/.*)?}mi', $url, $matches)
+            && $this->io->hasAuthentication((string) $matches['host'])
+        ) {
+            if ($matches['proto'] === 'ssh') {
+                $user = '';
+                if ($matches['user'] !== '' && $matches['user'] !== null) {
+                    $user = rawurlencode($matches['user']) . '@';
+                }
+                $authenticatedUrl = $matches['proto'] . '://' . $user . $matches['host'] . $matches['path'];
+            } else {
+                $auth = $this->io->getAuthentication((string) $matches['host']);
+                $authenticatedUrl = $matches['proto'] . '://' . rawurlencode($auth['username']) . ':' . rawurlencode($auth['password']) . '@' . $matches['host'] . $matches['path'];
+            }
             $command = $commandCallable($authenticatedUrl);
 
             if (0 === $this->process->execute($command, $ignoredOutput, $cwd)) {
@@ -70,10 +80,10 @@ class Hg
 
             $error = $this->process->getErrorOutput();
         } else {
-            $error = 'The given URL (' . $url . ') does not match the required format (http(s)://(username:password@)example.com/path-to-repository)';
+            $error = 'The given URL (' .$url. ') does not match the required format (ssh|http(s)://(username:password@)example.com/path-to-repository)';
         }
 
-        $this->throwException('Failed to clone ' . $url . ', ' . "\n\n" . $error, $url);
+        $this->throwException("Failed to clone $url, \n\n" . $error, $url);
     }
 
     /**
@@ -84,7 +94,9 @@ class Hg
     private function throwException($message, string $url): void
     {
         if (null === self::getVersion($this->process)) {
-            throw new \RuntimeException(Url::sanitize('Failed to clone ' . $url . ', hg was not found, check that it is installed and in your PATH env.' . "\n\n" . $this->process->getErrorOutput()));
+            throw new \RuntimeException(Url::sanitize(
+                'Failed to clone ' . $url . ', hg was not found, check that it is installed and in your PATH env.' . "\n\n" . $this->process->getErrorOutput()
+            ));
         }
 
         throw new \RuntimeException(Url::sanitize($message));