diff --git a/src/Test/PHPUnit/AbstractCacheConstraint.php b/src/Test/PHPUnit/AbstractCacheConstraint.php
index 6df827d4..61d027d4 100644
--- a/src/Test/PHPUnit/AbstractCacheConstraint.php
+++ b/src/Test/PHPUnit/AbstractCacheConstraint.php
@@ -44,6 +44,16 @@ abstract public function getValue();
      */
     protected function matches($other)
     {
+        if (!$other->hasHeader($this->header)) {
+            throw new \RuntimeException(
+                sprintf(
+                    'Response has no "%s" header. Configure your caching proxy '
+                    . 'to set the header with cache hit/miss status.',
+                    $this->header
+                )
+            );
+        }
+
         return $this->getValue() === (string) $other->getHeader($this->header);
     }
 
diff --git a/tests/Unit/Test/PHPUnit/AbstractCacheConstraintTest.php b/tests/Unit/Test/PHPUnit/AbstractCacheConstraintTest.php
new file mode 100644
index 00000000..5dc5290b
--- /dev/null
+++ b/tests/Unit/Test/PHPUnit/AbstractCacheConstraintTest.php
@@ -0,0 +1,14 @@
+<?php
+
+namespace FOS\HttpCache\Tests\Unit\Test\PHPUnit;
+
+abstract class AbstractCacheConstraintTest extends \PHPUnit_Framework_TestCase
+{
+    protected function getResponseMock()
+    {
+        return \Mockery::mock(
+            '\Guzzle\Http\Message\Response[hasHeader,getHeader]',
+            array(null)
+        );
+    }
+}
diff --git a/tests/Unit/Test/PHPUnit/IsCacheHitConstraintTest.php b/tests/Unit/Test/PHPUnit/IsCacheHitConstraintTest.php
index a81c9130..476fe842 100644
--- a/tests/Unit/Test/PHPUnit/IsCacheHitConstraintTest.php
+++ b/tests/Unit/Test/PHPUnit/IsCacheHitConstraintTest.php
@@ -13,7 +13,7 @@
 
 use FOS\HttpCache\Test\PHPUnit\IsCacheHitConstraint;
 
-class IsCacheHitConstraintTest extends \PHPUnit_Framework_TestCase
+class IsCacheHitConstraintTest extends AbstractCacheConstraintTest
 {
     /**
      * @var IsCacheHitConstraint
@@ -30,10 +30,23 @@ public function setUp()
      */
     public function testMatches()
     {
-        $response = \Mockery::mock('\Guzzle\Http\Message\Response[getHeader]', array(null))
-            ->shouldReceive('getHeader')
-            ->once()
-            ->andReturn('MISS')
+        $response = $this->getResponseMock()
+            ->shouldReceive('hasHeader')->with('cache-header')->andReturn(true)
+            ->shouldReceive('getHeader')->with('cache-header')->once()->andReturn('MISS')
+            ->getMock();
+
+        $this->constraint->evaluate($response);
+    }
+
+    /**
+     * @expectedException \RuntimeException
+     * @expectedExceptionMessage Response has no "cache-header" header
+     */
+    public function testMatchesThrowsExceptionIfHeaderIsMissing()
+    {
+        $response = $this->getResponseMock()
+            ->shouldReceive('hasHeader')->with('cache-header')->once()
+            ->andReturn(false)
             ->getMock();
 
         $this->constraint->evaluate($response);
diff --git a/tests/Unit/Test/PHPUnit/IsCacheMissConstraintTest.php b/tests/Unit/Test/PHPUnit/IsCacheMissConstraintTest.php
index 4f3e7fab..48b98756 100644
--- a/tests/Unit/Test/PHPUnit/IsCacheMissConstraintTest.php
+++ b/tests/Unit/Test/PHPUnit/IsCacheMissConstraintTest.php
@@ -13,7 +13,7 @@
 
 use FOS\HttpCache\Test\PHPUnit\IsCacheMissConstraint;
 
-class IsCacheMissConstraintTest extends \PHPUnit_Framework_TestCase
+class IsCacheMissConstraintTest extends AbstractCacheConstraintTest
 {
     /**
      * @var IsCacheMissConstraint
@@ -30,9 +30,9 @@ public function setUp()
      */
     public function testMatches()
     {
-        $response = \Mockery::mock('\Guzzle\Http\Message\Response[getHeader]', array(null))
-            ->shouldReceive('getHeader')
-            ->once()
+        $response = $this->getResponseMock()
+            ->shouldReceive('hasHeader')->with('cache-header')->andReturn(true)
+            ->shouldReceive('getHeader')->with('cache-header')->once()
             ->andReturn('HIT')
             ->getMock();