diff --git a/admin/tests/PreferencesCommandTest.php b/admin/tests/PreferencesCommandTest.php
index 4e537ae79c..6abec59e97 100644
--- a/admin/tests/PreferencesCommandTest.php
+++ b/admin/tests/PreferencesCommandTest.php
@@ -74,14 +74,15 @@ class PreferencesCommandTest extends CommandBase
 		// At type level
 	// DEBUG
 	echo "\n\n". __METHOD__ . "($type) after:\n";
-	$post_app = $post_pref->$type;
+		// Get type as an array since direct sub-access doesn't work in 5.6
+		$post_app = $post_pref->$type;
 	echo implode(', ',array_keys($post_pref->$type))."\n";
 	print_r($post_pref->$type[static::APP]);
 	echo "Does '".static::APP."' have the key? " . (array_key_exists($this->preference_name, $post_pref->$type[static::APP]) ? 'Yes' : 'No') . "\n";
 	echo "Does post_app have the key? " . (array_key_exists($this->preference_name, $post_app[static::APP]) ? 'Yes' : 'No') . "\n";
-		$this->assertArrayHasKey($this->preference_name, $post_pref->$type[static::APP],
+		$this->assertArrayHasKey($this->preference_name, $post_app[static::APP],
 				"$type preferences does not have {$this->preference_name}");
-		$this->assertEquals($set[$this->preference_name], $post_pref->$type[static::APP][$this->preference_name]);
+		$this->assertEquals($set[$this->preference_name], $post_app[static::APP][$this->preference_name]);
 
 		$this->assertGreaterThan($log_count, $this->get_log_count(), "Command ($command) did not log");
 	}