diff --git a/.gitignore b/.gitignore
index 22d0d82..fa36fe5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,3 @@
 vendor
+composer.lock
+.idea
diff --git a/Psr/Log/AbstractLogger.php b/Psr/Log/AbstractLogger.php
index 90e721a..3f17c86 100644
--- a/Psr/Log/AbstractLogger.php
+++ b/Psr/Log/AbstractLogger.php
@@ -19,7 +19,7 @@ abstract class AbstractLogger implements LoggerInterface
      *
      * @return void
      */
-    public function emergency($message, array $context = array())
+    public function emergency(string $message, array $context = []):void
     {
         $this->log(LogLevel::EMERGENCY, $message, $context);
     }
@@ -35,7 +35,7 @@ public function emergency($message, array $context = array())
      *
      * @return void
      */
-    public function alert($message, array $context = array())
+    public function alert(string $message, array $context = []):void
     {
         $this->log(LogLevel::ALERT, $message, $context);
     }
@@ -50,7 +50,7 @@ public function alert($message, array $context = array())
      *
      * @return void
      */
-    public function critical($message, array $context = array())
+    public function critical(string $message, array $context = []):void
     {
         $this->log(LogLevel::CRITICAL, $message, $context);
     }
@@ -64,7 +64,7 @@ public function critical($message, array $context = array())
      *
      * @return void
      */
-    public function error($message, array $context = array())
+    public function error(string $message, array $context = []):void
     {
         $this->log(LogLevel::ERROR, $message, $context);
     }
@@ -80,7 +80,7 @@ public function error($message, array $context = array())
      *
      * @return void
      */
-    public function warning($message, array $context = array())
+    public function warning(string $message, array $context = []):void
     {
         $this->log(LogLevel::WARNING, $message, $context);
     }
@@ -93,7 +93,7 @@ public function warning($message, array $context = array())
      *
      * @return void
      */
-    public function notice($message, array $context = array())
+    public function notice(string $message, array $context = []):void
     {
         $this->log(LogLevel::NOTICE, $message, $context);
     }
@@ -108,7 +108,7 @@ public function notice($message, array $context = array())
      *
      * @return void
      */
-    public function info($message, array $context = array())
+    public function info(string $message, array $context = []):void
     {
         $this->log(LogLevel::INFO, $message, $context);
     }
@@ -121,7 +121,7 @@ public function info($message, array $context = array())
      *
      * @return void
      */
-    public function debug($message, array $context = array())
+    public function debug(string $message, array $context = []):void
     {
         $this->log(LogLevel::DEBUG, $message, $context);
     }
diff --git a/Psr/Log/LoggerAwareInterface.php b/Psr/Log/LoggerAwareInterface.php
index 4d64f47..9f6e120 100644
--- a/Psr/Log/LoggerAwareInterface.php
+++ b/Psr/Log/LoggerAwareInterface.php
@@ -14,5 +14,5 @@ interface LoggerAwareInterface
      *
      * @return void
      */
-    public function setLogger(LoggerInterface $logger);
+    public function setLogger(LoggerInterface $logger):void;
 }
diff --git a/Psr/Log/LoggerAwareTrait.php b/Psr/Log/LoggerAwareTrait.php
index 639f79b..840530d 100644
--- a/Psr/Log/LoggerAwareTrait.php
+++ b/Psr/Log/LoggerAwareTrait.php
@@ -18,8 +18,10 @@ trait LoggerAwareTrait
      * Sets a logger.
      *
      * @param LoggerInterface $logger
+     *
+     * @return void
      */
-    public function setLogger(LoggerInterface $logger)
+    public function setLogger(LoggerInterface $logger):void
     {
         $this->logger = $logger;
     }
diff --git a/Psr/Log/LoggerInterface.php b/Psr/Log/LoggerInterface.php
index 5ea7243..fc3a210 100644
--- a/Psr/Log/LoggerInterface.php
+++ b/Psr/Log/LoggerInterface.php
@@ -27,7 +27,7 @@ interface LoggerInterface
      *
      * @return void
      */
-    public function emergency($message, array $context = array());
+    public function emergency(string $message, array $context = []):void;
 
     /**
      * Action must be taken immediately.
@@ -40,7 +40,7 @@ public function emergency($message, array $context = array());
      *
      * @return void
      */
-    public function alert($message, array $context = array());
+    public function alert(string $message, array $context = []):void;
 
     /**
      * Critical conditions.
@@ -52,7 +52,7 @@ public function alert($message, array $context = array());
      *
      * @return void
      */
-    public function critical($message, array $context = array());
+    public function critical(string $message, array $context = []):void;
 
     /**
      * Runtime errors that do not require immediate action but should typically
@@ -63,7 +63,7 @@ public function critical($message, array $context = array());
      *
      * @return void
      */
-    public function error($message, array $context = array());
+    public function error(string $message, array $context = []):void;
 
     /**
      * Exceptional occurrences that are not errors.
@@ -76,7 +76,7 @@ public function error($message, array $context = array());
      *
      * @return void
      */
-    public function warning($message, array $context = array());
+    public function warning(string $message, array $context = []):void;
 
     /**
      * Normal but significant events.
@@ -86,7 +86,7 @@ public function warning($message, array $context = array());
      *
      * @return void
      */
-    public function notice($message, array $context = array());
+    public function notice(string $message, array $context = []):void;
 
     /**
      * Interesting events.
@@ -98,7 +98,7 @@ public function notice($message, array $context = array());
      *
      * @return void
      */
-    public function info($message, array $context = array());
+    public function info(string $message, array $context = []):void;
 
     /**
      * Detailed debug information.
@@ -108,7 +108,7 @@ public function info($message, array $context = array());
      *
      * @return void
      */
-    public function debug($message, array $context = array());
+    public function debug(string $message, array $context = []):void;
 
     /**
      * Logs with an arbitrary level.
@@ -119,5 +119,5 @@ public function debug($message, array $context = array());
      *
      * @return void
      */
-    public function log($level, $message, array $context = array());
+    public function log($level, string $message, array $context = []):void;
 }
diff --git a/Psr/Log/LoggerTrait.php b/Psr/Log/LoggerTrait.php
index 867225d..82432b9 100644
--- a/Psr/Log/LoggerTrait.php
+++ b/Psr/Log/LoggerTrait.php
@@ -20,7 +20,7 @@ trait LoggerTrait
      *
      * @return void
      */
-    public function emergency($message, array $context = array())
+    public function emergency(string $message, array $context = []):void
     {
         $this->log(LogLevel::EMERGENCY, $message, $context);
     }
@@ -36,7 +36,7 @@ public function emergency($message, array $context = array())
      *
      * @return void
      */
-    public function alert($message, array $context = array())
+    public function alert(string $message, array $context = []):void
     {
         $this->log(LogLevel::ALERT, $message, $context);
     }
@@ -51,7 +51,7 @@ public function alert($message, array $context = array())
      *
      * @return void
      */
-    public function critical($message, array $context = array())
+    public function critical(string $message, array $context = []):void
     {
         $this->log(LogLevel::CRITICAL, $message, $context);
     }
@@ -65,7 +65,7 @@ public function critical($message, array $context = array())
      *
      * @return void
      */
-    public function error($message, array $context = array())
+    public function error(string $message, array $context = []):void
     {
         $this->log(LogLevel::ERROR, $message, $context);
     }
@@ -81,7 +81,7 @@ public function error($message, array $context = array())
      *
      * @return void
      */
-    public function warning($message, array $context = array())
+    public function warning(string $message, array $context = []):void
     {
         $this->log(LogLevel::WARNING, $message, $context);
     }
@@ -94,7 +94,7 @@ public function warning($message, array $context = array())
      *
      * @return void
      */
-    public function notice($message, array $context = array())
+    public function notice(string $message, array $context = []):void
     {
         $this->log(LogLevel::NOTICE, $message, $context);
     }
@@ -109,7 +109,7 @@ public function notice($message, array $context = array())
      *
      * @return void
      */
-    public function info($message, array $context = array())
+    public function info(string $message, array $context = []):void
     {
         $this->log(LogLevel::INFO, $message, $context);
     }
@@ -122,7 +122,7 @@ public function info($message, array $context = array())
      *
      * @return void
      */
-    public function debug($message, array $context = array())
+    public function debug(string $message, array $context = []):void
     {
         $this->log(LogLevel::DEBUG, $message, $context);
     }
@@ -136,5 +136,5 @@ public function debug($message, array $context = array())
      *
      * @return void
      */
-    abstract public function log($level, $message, array $context = array());
+    abstract public function log($level, string $message, array $context = []):void;
 }
diff --git a/Psr/Log/NullLogger.php b/Psr/Log/NullLogger.php
index d8cd682..d67fd91 100644
--- a/Psr/Log/NullLogger.php
+++ b/Psr/Log/NullLogger.php
@@ -21,7 +21,7 @@ class NullLogger extends AbstractLogger
      *
      * @return void
      */
-    public function log($level, $message, array $context = array())
+    public function log($level, string $message, array $context = []):void
     {
         // noop
     }
diff --git a/composer.json b/composer.json
index 87934d7..4358b91 100644
--- a/composer.json
+++ b/composer.json
@@ -11,7 +11,7 @@
         }
     ],
     "require": {
-        "php": ">=5.3.0"
+        "php": ">=7.1.0"
     },
     "autoload": {
         "psr-4": {
@@ -20,7 +20,7 @@
     },
     "extra": {
         "branch-alias": {
-            "dev-master": "1.0.x-dev"
+            "dev-master": "2.0.x-dev"
         }
     }
 }