diff --git a/.travis.composer.config.json.enc b/.travis.composer.config.json.enc
deleted file mode 100644
index adc550e..0000000
--- a/.travis.composer.config.json.enc
+++ /dev/null
@@ -1,2 +0,0 @@
-I“’mƒ-
lµözh—n•VyÉô®kž×™«ëÃ)‚¹=ºÑW/X	¨}
-ìtÝXÉÑÂ)˜¼:܃,&”dlÉ	Ûoí!¶6Îâ̺[å’ûšB{·Š M9[óuúhéF`d­™'1àm¨0D‡}c0$î£Ç¯Ð
\ No newline at end of file
diff --git a/.travis.yml b/.travis.yml
index 1f34339..1433803 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,17 +1,15 @@
 language: php
 
 php:
-  - 7.0
+  - 7.3
+  - 7.4snapshot
   - nightly
 
 matrix:
   fast_finish: true
   allow_failures:
     - php: nightly
-
-before_install:
-  - "mkdir -p ~/.composer"
-  - openssl aes-256-cbc -K $encrypted_00d4fc3a7399_key -iv $encrypted_00d4fc3a7399_iv -in .travis.composer.config.json.enc -out ~/.composer/config.json -d
+    - php: 7.4snapshot
 
 install:
   - composer install
@@ -20,5 +18,7 @@ script:
   - vendor/bin/phpunit --coverage-text
 
 after_success:
-  - composer require satooshi/php-coveralls
-  - vendor/bin/coveralls
+  - composer require php-coveralls/php-coveralls
+  - travis_retry vendor/bin/php-coveralls
+  - composer require phpstan/phpstan
+  - vendor/bin/phpstan analyse src/
diff --git a/CHANGELOG.md b/CHANGELOG.md
index c40e82e..152b82a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Changelog
 
+## 6.0.0 (2019-11-12)
+
+### BC breaks
+
+* raised minimum required PHP version to 7.3
+
 ## 5.0.0 (2016-07-31)
 
 ### BC breaks
diff --git a/README.md b/README.md
index f02a5d4..394653c 100644
--- a/README.md
+++ b/README.md
@@ -20,10 +20,10 @@ _stubbles/image is distributed as [Composer](https://getcomposer.org/)
 package. To install it as a dependency of your package use the following
 command:
 
-    composer require "stubbles/image": "^5.0"
+    composer require "stubbles/image": "^6.0"
 
 
 Requirements
 ------------
 
-_stubbles/image_ requires at least PHP 7.0.
+_stubbles/image_ requires at least PHP 7.3.
diff --git a/composer.json b/composer.json
index cbf018b..dfb65af 100644
--- a/composer.json
+++ b/composer.json
@@ -5,7 +5,7 @@
     "license": "BSD-3-Clause",
     "description": "Simple image handling support.",
     "require": {
-        "php": "^7.0",
+        "php": "^7.3",
         "ext-gd": "*"
     },
     "require-dev": {
@@ -24,7 +24,7 @@
     },
     "extra": {
         "branch-alias": {
-            "dev-master": "5.0.x-dev"
+            "dev-master": "6.0.x-dev"
         }
     },
     "minimum-stability": "dev",
diff --git a/composer.lock b/composer.lock
index 76345c8..6dd2bbd 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "289e0f6c3f95a447d2b3edce59243314",
+    "content-hash": "dc7ae15b44ae3dd6bdafe9b68054eac4",
     "packages": [],
     "packages-dev": [
         {
@@ -1576,7 +1576,7 @@
     "prefer-stable": true,
     "prefer-lowest": false,
     "platform": {
-        "php": "^7.0",
+        "php": "^7.3",
         "ext-gd": "*"
     },
     "platform-dev": []