diff --git a/test/AssertTest.php b/test/AssertTest.php
index bc5b1c7..2eb41df 100644
--- a/test/AssertTest.php
+++ b/test/AssertTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 use PHPUnit\Framework\TestCase;
 
 class AssertTest extends TestCase
@@ -11,7 +13,8 @@ class AssertTest extends TestCase
     public static function doSetUpBeforeClass() {
         self::$tm = ini_get("tarantool.request_timeout");
         ini_set("tarantool.request_timeout", "0.1");
-        self::$tarantool = new Tarantool('localhost', getenv('PRIMARY_PORT'));
+        $port = TestHelpers::getTarantoolPort();
+        self::$tarantool = new Tarantool('localhost', $port);
         self::$tarantool->authenticate('test', 'test');
     }
 
diff --git a/test/CreateTest.php b/test/CreateTest.php
index 02d8fd9..f49310b 100644
--- a/test/CreateTest.php
+++ b/test/CreateTest.php
@@ -9,7 +9,7 @@ class CreateTest extends TestCase
     protected static $port, $tm;
 
     public static function doSetUpBeforeClass() {
-        self::$port = getenv('PRIMARY_PORT');
+        self::$port = TestHelpers::getTarantoolPort();
         self::$tm = ini_get("tarantool.timeout");
         // error_log("before setting tarantool timeout");
         ini_set("tarantool.timeout", "0.1");
diff --git a/test/DMLTest.php b/test/DMLTest.php
index fb365bc..1ecff82 100644
--- a/test/DMLTest.php
+++ b/test/DMLTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 use PHPUnit\Framework\TestCase;
 
 class DMLTest extends TestCase
@@ -10,7 +12,8 @@ class DMLTest extends TestCase
 
     public static function doSetUpBeforeClass()
     {
-        self::$tarantool = new Tarantool('localhost', getenv('PRIMARY_PORT'), 'test', 'test');
+        $port = TestHelpers::getTarantoolPort();
+        self::$tarantool = new Tarantool('localhost', $port, 'test', 'test');
     }
 
     protected function doTearDown()
diff --git a/test/MockTest.php b/test/MockTest.php
index 3f5a49c..424d8ba 100644
--- a/test/MockTest.php
+++ b/test/MockTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 use PHPUnit\Framework\TestCase;
 
 class MockTest extends TestCase
@@ -14,7 +16,8 @@ public function testFoo()
     public function testDoo()
     {
         try {
-            (new Tarantool('localhost', getenv('PRIMARY_PORT')))->select('_vindex', [], 'name');
+            $port = testHelpers::getTarantoolPort();
+            (new Tarantool('localhost', $port))->select('_vindex', [], 'name');
             $this->assertFalse(True);
         } catch (Exception $e) {
            $this->assertTrue(True);
diff --git a/test/MsgPackTest.php b/test/MsgPackTest.php
index 6ff805a..ddc2c08 100644
--- a/test/MsgPackTest.php
+++ b/test/MsgPackTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 use PHPUnit\Framework\TestCase;
 
 class MsgPackTest extends TestCase
@@ -10,7 +12,8 @@ class MsgPackTest extends TestCase
 
     public static function doSetUpBeforeClass()
     {
-        self::$tarantool = new Tarantool('localhost', getenv('PRIMARY_PORT'), 'test', 'test');
+        $port = TestHelpers::getTarantoolPort();
+        self::$tarantool = new Tarantool('localhost', $port, 'test', 'test');
         self::$tarantool->ping();
     }
 
diff --git a/test/RandomTest.php b/test/RandomTest.php
index b4e1c76..9eb60d1 100644
--- a/test/RandomTest.php
+++ b/test/RandomTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 function generateRandomString($length = 10) {
     $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
     $charactersLength = strlen($characters);
@@ -19,7 +21,8 @@ class RandomTest extends TestCase
     protected static $tarantool;
 
     public static function doSetUpBeforeClass() {
-        self::$tarantool = new Tarantool('localhost', getenv('PRIMARY_PORT'), 'test', 'test');
+        $port = TestHelpers::getTarantoolPort();
+        self::$tarantool = new Tarantool('localhost', $port, 'test', 'test');
         self::$tarantool->ping();
     }
 
diff --git a/test/TestHelpers.php b/test/TestHelpers.php
new file mode 100644
index 0000000..7e1f381
--- /dev/null
+++ b/test/TestHelpers.php
@@ -0,0 +1,24 @@
+<?php
+
+/*
+ * Set of utility functions for testing.
+ */
+final class TestHelpers {
+    /*
+     * Get a port number, where tarantool expects binary protocol
+     * clients.
+     *
+     * The source of information is PRIMARY_PORT environment
+     * variable, which is set by the test-run.py script.
+     *
+     * If it is not set for some reason, the function will raise
+     * an exception.
+     */
+    public static function getTarantoolPort() {
+        $port = intval(getenv('PRIMARY_PORT'));
+        if ($port == 0)
+            throw new Exception(
+                'Unable to parse PRIMARY_PORT environment variable as int');
+        return $port;
+    }
+};
diff --git a/test/bootstrap.php b/test/bootstrap.php
index e12b814..7d2d825 100644
--- a/test/bootstrap.php
+++ b/test/bootstrap.php
@@ -1,3 +1,4 @@
 <?php
 
 require __DIR__ . '/PhpUnitCompat.php';
+require __DIR__ . '/TestHelpers.php';