diff --git a/framework/CHANGELOG.md b/framework/CHANGELOG.md
index 3c1c369fd2..0e9b088038 100644
--- a/framework/CHANGELOG.md
+++ b/framework/CHANGELOG.md
@@ -30,6 +30,7 @@ Yii Framework 2 Change Log
 - Bug #9915: `yii\helpers\ArrayHelper::getValue()` was erroring instead of returning `null` for non-existing object properties (totaldev, samdark)
 - Bug #9924: Fixed `yii.js` handleAction corrupted parameter values containing quote (") character (silverfire)
 - Bug #9984: Fixed wrong captcha color in case Imagick is used (DrDeath72)
+- Bug #9999: Fixed `yii\web\UrlRule` to allow route parameter names with `-`, `_`, `.`characters (silverfire)
 - Bug #10029: Fixed MaskedInput not working with PJAX (martrix78, samdark)
 - Bug: Fixed generation of canonical URLs for `ViewAction` pages (samdark)
 - Enh #3506: Added `\yii\validators\IpValidator` to perform validation of IP addresses and subnets (SilverFire, samdark)
diff --git a/framework/web/UrlRule.php b/framework/web/UrlRule.php
index c0ba9ed295..daabcac144 100644
--- a/framework/web/UrlRule.php
+++ b/framework/web/UrlRule.php
@@ -104,6 +104,18 @@ class UrlRule extends Object implements UrlRuleInterface
      * @var array list of parameters used in the route.
      */
     private $_routeParams = [];
+    /**
+     * @var array list of placeholders for matching parameters names. Used in [[parseRequest()]], [[createUrl()]]
+     * On the rule initialization, the [[pattern]] parameters names will be replaced with placeholders.
+     * This array contains relations between the original parameters names and their placeholders.
+     *  key - placeholder
+     *  value - original name
+     *
+     * @see parseRequest()
+     * @see createUrl()
+     * @since 2.0.7
+     */
+    private $_placeholders = [];
 
 
     /**
@@ -151,7 +163,7 @@ class UrlRule extends Object implements UrlRuleInterface
             $this->pattern = '/' . $this->pattern . '/';
         }
 
-        if (strpos($this->route, '<') !== false && preg_match_all('/<(\w+)>/', $this->route, $matches)) {
+        if (strpos($this->route, '<') !== false && preg_match_all('/<([\w._-]+)>/', $this->route, $matches)) {
             foreach ($matches[1] as $name) {
                 $this->_routeParams[$name] = "<$name>";
             }
@@ -166,31 +178,34 @@ class UrlRule extends Object implements UrlRuleInterface
             '(' => '\\(',
             ')' => '\\)',
         ];
+
         $tr2 = [];
-        if (preg_match_all('/<(\w+):?([^>]+)?>/', $this->pattern, $matches, PREG_OFFSET_CAPTURE | PREG_SET_ORDER)) {
+        if (preg_match_all('/<([\w._-]+):?([^>]+)?>/', $this->pattern, $matches, PREG_OFFSET_CAPTURE | PREG_SET_ORDER)) {
             foreach ($matches as $match) {
                 $name = $match[1][0];
                 $pattern = isset($match[2][0]) ? $match[2][0] : '[^\/]+';
+                $placeholder = 'a' . hash('crc32b', $name); // placeholder must begin with a letter
+                $this->_placeholders[$placeholder] = $name;
                 if (array_key_exists($name, $this->defaults)) {
                     $length = strlen($match[0][0]);
                     $offset = $match[0][1];
                     if ($offset > 1 && $this->pattern[$offset - 1] === '/' && (!isset($this->pattern[$offset + $length]) || $this->pattern[$offset + $length] === '/')) {
-                        $tr["/<$name>"] = "(/(?P<$name>$pattern))?";
+                        $tr["/<$name>"] = "(/(?P<$placeholder>$pattern))?";
                     } else {
-                        $tr["<$name>"] = "(?P<$name>$pattern)?";
+                        $tr["<$name>"] = "(?P<$placeholder>$pattern)?";
                     }
                 } else {
-                    $tr["<$name>"] = "(?P<$name>$pattern)";
+                    $tr["<$name>"] = "(?P<$placeholder>$pattern)";
                 }
                 if (isset($this->_routeParams[$name])) {
-                    $tr2["<$name>"] = "(?P<$name>$pattern)";
+                    $tr2["<$name>"] = "(?P<$placeholder>$pattern)";
                 } else {
                     $this->_paramRules[$name] = $pattern === '[^\/]+' ? '' : "#^$pattern$#u";
                 }
             }
         }
 
-        $this->_template = preg_replace('/<(\w+):?([^>]+)?>/', '<$1>', $this->pattern);
+        $this->_template = preg_replace('/<([\w._-]+):?([^>]+)?>/', '<$1>', $this->pattern);
         $this->pattern = '#^' . trim(strtr($this->_template, $tr), '/') . '$#u';
 
         if (!empty($this->_routeParams)) {
@@ -216,7 +231,7 @@ class UrlRule extends Object implements UrlRuleInterface
         }
 
         $pathInfo = $request->getPathInfo();
-        $suffix = (string) ($this->suffix === null ? $manager->suffix : $this->suffix);
+        $suffix = (string)($this->suffix === null ? $manager->suffix : $this->suffix);
         if ($suffix !== '' && $pathInfo !== '') {
             $n = strlen($suffix);
             if (substr_compare($pathInfo, $suffix, -$n, $n) === 0) {
@@ -237,6 +252,8 @@ class UrlRule extends Object implements UrlRuleInterface
         if (!preg_match($this->pattern, $pathInfo, $matches)) {
             return false;
         }
+        $matches = $this->substitutePlaceholderNames($matches);
+
         foreach ($this->defaults as $name => $value) {
             if (!isset($matches[$name]) || $matches[$name] === '') {
                 $matches[$name] = $value;
@@ -281,6 +298,7 @@ class UrlRule extends Object implements UrlRuleInterface
         // match the route part first
         if ($route !== $this->route) {
             if ($this->_routeRule !== null && preg_match($this->_routeRule, $route, $matches)) {
+                $matches = $this->substitutePlaceholderNames($matches);
                 foreach ($this->_routeParams as $name => $token) {
                     if (isset($this->defaults[$name]) && strcmp($this->defaults[$name], $matches[$name]) === 0) {
                         $tr[$token] = '';
@@ -352,4 +370,34 @@ class UrlRule extends Object implements UrlRuleInterface
     {
         return $this->_paramRules;
     }
-}
+
+    /**
+     * Iterates over [[_placeholders]] and checks whether each placeholder exists as a key in $matches array.
+     * When found - replaces this placeholder key with a appropriate name of matching parameter.
+     * Used in [[parseRequest()]], [[createUrl()]].
+     *
+     * @param array $matches result of `preg_match()` call
+     * @return array input array with replaced placeholder keys
+     * @see _placeholders
+     * @since 2.0.7
+     */
+    private function substitutePlaceholderNames (array $matches) {
+        foreach ($this->_placeholders as $placeholder => $name) {
+            if (isset($matches[$placeholder])) {
+                $matches[$name] = $matches[$placeholder];
+                unset($matches[$placeholder]);
+            }
+        }
+        return $matches;
+    }
+
+    /**
+     * Returns list of placeholders and original names for matching parameters.
+     * @return array
+     * @since 2.0.7
+     * @see _placeholders
+     */
+    protected function getPlaceholders() {
+        return $this->_placeholders;
+    }
+}
\ No newline at end of file