diff --git a/test/AggregatePoolTest.php b/test/AggregatePoolTest.php
index 16ece97..bbdab60 100644
--- a/test/AggregatePoolTest.php
+++ b/test/AggregatePoolTest.php
@@ -4,8 +4,7 @@ namespace Amp\Postgres\Test;
 
 use Amp\Postgres\AggregatePool;
 
-class AggregatePoolTest extends AbstractPoolTest
-{
+class AggregatePoolTest extends AbstractPoolTest {
     /**
      * @param array $connections
      *
diff --git a/test/ConnectionPoolTest.php b/test/ConnectionPoolTest.php
index f09e542..d55fe06 100644
--- a/test/ConnectionPoolTest.php
+++ b/test/ConnectionPoolTest.php
@@ -6,8 +6,7 @@ use Amp\Postgres\ConnectionPool;
 use Amp\Success;
 use Interop\Async\Awaitable;
 
-class ConnectionPoolTest extends AbstractPoolTest
-{
+class ConnectionPoolTest extends AbstractPoolTest {
     /**
      * @param array $connections
      *
diff --git a/test/FunctionsTest.php b/test/FunctionsTest.php
index de19109..5b597a3 100644
--- a/test/FunctionsTest.php
+++ b/test/FunctionsTest.php
@@ -4,8 +4,13 @@ namespace Amp\Postgres\Test;
 
 use Amp\Postgres\{ Connection, function connect };
 
-class FunctionsTest extends \PHPUnit_Framework_TestCase
-{
+class FunctionsTest extends \PHPUnit_Framework_TestCase {
+    public function setUp() {
+        if (!\extension_loaded('pgsql') && !\extension_loaded('pq')) {
+            $this->markTestSkipped('This test requires either ext/pgsql or pecl/pq');
+        }
+    }
+
     public function testConnect() {
         \Amp\execute(function () {
             $connection = yield connect('host=localhost user=postgres', 1);
diff --git a/test/PgSqlConnectionTest.php b/test/PgSqlConnectionTest.php
index 9c56772..5434072 100644
--- a/test/PgSqlConnectionTest.php
+++ b/test/PgSqlConnectionTest.php
@@ -4,6 +4,9 @@ namespace Amp\Postgres\Test;
 
 use Amp\Postgres\{ Connection, PgSqlConnection };
 
+/**
+ * @requires extension pgsql
+ */
 class PgSqlConnectionTest extends AbstractConnectionTest {
     /** @var resource PostgreSQL connection resource. */
     protected $handle;
diff --git a/test/PqConnectionTest.php b/test/PqConnectionTest.php
index b112f46..9946fb6 100644
--- a/test/PqConnectionTest.php
+++ b/test/PqConnectionTest.php
@@ -4,6 +4,9 @@ namespace Amp\Postgres\Test;
 
 use Amp\Postgres\{ Connection, PqConnection };
 
+/**
+ * @requires extension pq
+ */
 class PqConnectionTest extends AbstractConnectionTest {
     /** @var resource PostgreSQL connection resource. */
     protected $handle;