diff --git a/src/composer.json b/src/composer.json
index a6716fcb..4c7c748d 100644
--- a/src/composer.json
+++ b/src/composer.json
@@ -25,7 +25,8 @@
         "symfony/yaml": "2.5.*",
         "symfony/translation": "2.5.*",
         "tedivm/stash": "0.12.*",
-        "canteen/html5": "1.1.*"
+        "canteen/html5": "1.1.*",
+        "vierbergenlars/php-semver": "3.0.*"
     },
     "require-dev": {
         "squizlabs/php_codesniffer": "1.*"
diff --git a/src/mibew/libs/classes/Mibew/Plugin/Manager.php b/src/mibew/libs/classes/Mibew/Plugin/Manager.php
index d7235cde..7be7f2eb 100644
--- a/src/mibew/libs/classes/Mibew/Plugin/Manager.php
+++ b/src/mibew/libs/classes/Mibew/Plugin/Manager.php
@@ -19,6 +19,9 @@
 
 namespace Mibew\Plugin;
 
+use vierbergenlars\SemVer\version as Version;
+use vierbergenlars\SemVer\expression as VersionExpression;
+
 /**
  * Manage plugins
  */
@@ -141,12 +144,13 @@ class Manager
                     continue 2;
                 }
 
+                $version_constrain = new VersionExpression($required_version);
                 $dependency_version = call_user_func(array(
                     self::$loadedPlugins[$dependency],
                     'getVersion'
                 ));
 
-                if ($required_version !== $dependency_version) {
+                if (!$version_constrain->satisfiedBy(new Version($dependency_version))) {
                     $error_message = "Plugin '{$dependency}' has version "
                         . "incompatible with '{$plugin_name}' requirements!";
                     trigger_error($error_message, E_USER_WARNING);
diff --git a/src/mibew/libs/classes/Mibew/Plugin/PluginInterface.php b/src/mibew/libs/classes/Mibew/Plugin/PluginInterface.php
index dee93479..cfcd9c8a 100644
--- a/src/mibew/libs/classes/Mibew/Plugin/PluginInterface.php
+++ b/src/mibew/libs/classes/Mibew/Plugin/PluginInterface.php
@@ -61,8 +61,22 @@ interface PluginInterface
      * Returns list of plugin's dependencies.
      *
      * Each key in the array is a string with a plugin name. Each value is
-     * required plugin version. If the plugin have no dependencies an empty
-     * array should be returned.
+     * plugin version constrain. A constrain can be in one of the following
+     * formats:
+     *  - "1.2.3": exact version number;
+     *  - ">1.2.3": grater than a specific version;
+     *  - ">=1.2.3": greater than a specific version or equal to it;
+     *  - "<1.2.3": less than a specific version;
+     *  - "<=1.2.3": less than a specific version or equal to it;
+     *  - "1.2.3 - 2.3.4": equals to ">=1.2.3 <=2.3.4";
+     *  - "~1.2.3": equivalent for ">=1.2.3 <1.3.0";
+     *  - "~1.2": equivalent for ">=1.2.0 <2.0.0";
+     *  - "^1.2.3" equivalent for ">=1.2.3 <2.0.0";
+     *  - "^0.1.2" equivalent for ">=0.1.2 <0.2.0";
+     *  - "1.2.x": equivalent for ">=1.2.0 <2.0.0";
+     *  - "1.x": equivalent for ">=1.0.0 <2.0.0";
+     *
+     * If the plugin have no dependencies an empty array should be returned.
      *
      * @return array List of plugin's dependencies.
      */