diff --git a/.travis.yml b/.travis.yml
index b7459a0..c8b8682 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,6 +5,7 @@ php:
     - 5.6
     - 7.0
     - 7.1
+    - 7.2
     - hhvm
 
 before_install:
diff --git a/src/Finite/StateMachine/StateMachine.php b/src/Finite/StateMachine/StateMachine.php
index 47caad8..0f4b6e1 100644
--- a/src/Finite/StateMachine/StateMachine.php
+++ b/src/Finite/StateMachine/StateMachine.php
@@ -223,7 +223,7 @@ public function getTransition($name)
             throw new Exception\TransitionException(sprintf(
                 'Unable to find a transition called "%s" on object "%s" with graph "%s".',
                 $name,
-                get_class($this->getObject()),
+                ($object = $this->getObject()) ? get_class($object) : 'null',
                 $this->getGraph()
             ));
         }
@@ -242,7 +242,7 @@ public function getState($name)
             throw new Exception\StateException(sprintf(
                 'Unable to find a state called "%s" on object "%s" with graph "%s".',
                 $name,
-                get_class($this->getObject()),
+                ($object = $this->getObject()) ? get_class($this->getObject()) : 'null',
                 $this->getGraph()
             ));
         }
@@ -307,7 +307,7 @@ protected function findInitialState()
 
         throw new Exception\StateException(sprintf(
             'No initial state found on object "%s" with graph "%s".',
-            get_class($this->getObject()),
+            ($object = $this->getObject()) ? get_class($object) : 'null',
             $this->getGraph()
         ));
     }