core/modules/system/src/Tests/Entity/EntityCacheTagsTestBase.php | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/core/modules/system/src/Tests/Entity/EntityCacheTagsTestBase.php b/core/modules/system/src/Tests/Entity/EntityCacheTagsTestBase.php
index 53fdd03..e33ee24 100644
--- a/core/modules/system/src/Tests/Entity/EntityCacheTagsTestBase.php
+++ b/core/modules/system/src/Tests/Entity/EntityCacheTagsTestBase.php
@@ -394,7 +394,7 @@ public function testReferencedEntity() {
     $this->verifyPageCache($empty_entity_listing_url, 'HIT', $empty_entity_listing_cache_tags);
     // Verify the entity type's list cache contexts are present.
     $contexts_in_header = $this->drupalGetHeader('X-Drupal-Cache-Contexts');
-    $this->assertEqual($this->getAdditionalCacheContextsForEntityListing(), explode(' ', $this->drupalGetHeader('X-Drupal-Cache-Contexts')));
+    $this->assertEqual($this->getAdditionalCacheContextsForEntityListing(), empty($contexts_in_header) ? [] : explode(' ', $contexts_in_header));
 
 
     $this->pass("Test listing containing referenced entity.", 'Debug');
@@ -403,7 +403,8 @@ public function testReferencedEntity() {
     // Verify a cache hit, but also the presence of the correct cache tags.
     $this->verifyPageCache($nonempty_entity_listing_url, 'HIT', $nonempty_entity_listing_cache_tags);
     // Verify the entity type's list cache contexts are present.
-    $this->assertEqual($this->getAdditionalCacheContextsForEntityListing(), explode(' ', $this->drupalGetHeader('X-Drupal-Cache-Contexts')));
+    $contexts_in_header = $this->drupalGetHeader('X-Drupal-Cache-Contexts');
+    $this->assertEqual($this->getAdditionalCacheContextsForEntityListing(), empty($contexts_in_header) ? [] : explode(' ', $contexts_in_header));
 
 
     // Verify that after modifying the referenced entity, there is a cache miss