diff --git a/.github/workflows/integration.yml b/.github/workflows/integration.yml
index cb6b363..925ae87 100644
--- a/.github/workflows/integration.yml
+++ b/.github/workflows/integration.yml
@@ -41,4 +41,4 @@ jobs:
       run: tools/phpcs --standard=psr12 src tests
 
     - name: Static code analysis
-      run: tools/phpstan analyse
+      run: tools/phpstan analyse -c phpstan-${{ matrix.php-versions }}.neon
diff --git a/phive.xml b/phive.xml
index 55d8d8a..ea7b0a4 100644
--- a/phive.xml
+++ b/phive.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <phive xmlns="https://phar.io/phive">
-  <phar name="phpunit" version="^9.0.0" installed="9.5.0" location="./tools/phpunit" copy="true"/>
-  <phar name="phpcs" version="^3.5.2" installed="3.5.8" location="./tools/phpcs" copy="true"/>
-  <phar name="phpstan" version="^0.12.2" installed="0.12.59" location="./tools/phpstan" copy="true"/>
+  <phar name="phpunit" version="^9.0.0" installed="9.5.10" location="./tools/phpunit" copy="true"/>
+  <phar name="phpcs" version="^3.5.2" installed="3.6.1" location="./tools/phpcs" copy="true"/>
+  <phar name="phpstan" version="^0.12.2" installed="0.12.99" location="./tools/phpstan" copy="true"/>
 </phive>
diff --git a/phpstan-7.3.neon b/phpstan-7.3.neon
new file mode 100644
index 0000000..f4476cb
--- /dev/null
+++ b/phpstan-7.3.neon
@@ -0,0 +1,4 @@
+parameters:
+  level: 5
+  paths:
+  - %currentWorkingDirectory%/src/
diff --git a/phpstan-7.4.neon b/phpstan-7.4.neon
new file mode 100644
index 0000000..f4476cb
--- /dev/null
+++ b/phpstan-7.4.neon
@@ -0,0 +1,4 @@
+parameters:
+  level: 5
+  paths:
+  - %currentWorkingDirectory%/src/
diff --git a/phpstan-8.0.neon b/phpstan-8.0.neon
new file mode 100644
index 0000000..2bb2649
--- /dev/null
+++ b/phpstan-8.0.neon
@@ -0,0 +1,6 @@
+parameters:
+  level: 5
+  paths:
+  - %currentWorkingDirectory%/src/
+  ignoreErrors:
+    - '#Left side of && is always true#'
diff --git a/src/Command/Executable.php b/src/Command/Executable.php
index 7a4c812..beb0024 100644
--- a/src/Command/Executable.php
+++ b/src/Command/Executable.php
@@ -45,6 +45,13 @@ class Executable implements Command
      */
     private $options = [];
 
+    /**
+     * List of variables to define
+     *
+     * @var string[]
+     */
+    private $vars = [];
+
     /**
      * List of acceptable exit codes.
      *
@@ -71,9 +78,9 @@ public function __construct(string $cmd, array $exitCodes = [0])
      */
     public function getCommand(): string
     {
-        $cmd = sprintf('"%s"', $this->cmd)
-            . (count($this->options)   ? ' ' . implode(' ', $this->options)   : '')
-            . ($this->isSilent         ? ' 2> /dev/null'                      : '');
+        $cmd = $this->getVars() . sprintf('"%s"', $this->cmd)
+             . (count($this->options)   ? ' ' . implode(' ', $this->options)   : '')
+             . ($this->isSilent         ? ' 2> /dev/null'                      : '');
 
         return Util::escapeSpacesIfOnWindows($cmd);
     }
@@ -125,6 +132,36 @@ public function addOption(string $option, $value = null, string $glue = '='): Ex
         return $this;
     }
 
+    /**
+     * Add a var definition to a command
+     *
+     * @param  string $name
+     * @param  string $value
+     * @return $this
+     */
+    public function addVar(string $name, string $value): Executable
+    {
+        $this->vars[$name] = $value;
+
+        return $this;
+    }
+
+    /**
+     * Return variable definition string e.g. "MYFOO='sometext' MYBAR='nothing' "
+     *
+     * @return string
+     */
+    protected function getVars(): string
+    {
+        $varStrings = [];
+
+        foreach ($this->vars as $name => $value) {
+            $varStrings[] = $name . '=' . escapeshellarg($value);
+        }
+
+        return count($varStrings) ? implode(' ', $varStrings) . ' ' : '';
+    }
+
     /**
      * Adds an option to a command if it is not empty.
      *
diff --git a/tests/cli/Command/ExecutableTest.php b/tests/cli/Command/ExecutableTest.php
index 9590fad..d903a11 100644
--- a/tests/cli/Command/ExecutableTest.php
+++ b/tests/cli/Command/ExecutableTest.php
@@ -107,4 +107,17 @@ public function testAddOptionIfEmptyAsValue()
 
         $this->assertEquals('"foo" -bar=\'fiz\'', (string) $cmd, 'option should be added');
     }
+
+    /**
+     * Tests Executable::addVar
+     */
+    public function testAddVar()
+    {
+        $cmd = new Executable('tool');
+        $cmd->addVar('FOO', 'fiz');
+        $cmd->addVar('BAR', 'baz');
+        $cmd->addOptionIfNotEmpty('--extra', 'bonus');
+
+        $this->assertEquals('FOO=\'fiz\' BAR=\'baz\' "tool" --extra=\'bonus\'', (string) $cmd, 'vars prefix');
+    }
 }