diff --git a/builder/amazon/common/step_run_source_instance.go b/builder/amazon/common/step_run_source_instance.go
index 34146081d..ee0cf0eb5 100644
--- a/builder/amazon/common/step_run_source_instance.go
+++ b/builder/amazon/common/step_run_source_instance.go
@@ -95,7 +95,7 @@ func (s *StepRunSourceInstance) Run(state multistep.StateBag) multistep.StepActi
 		state.Put("error", fmt.Errorf(
 			"The provided source AMI has an invalid root device type.\n"+
 				"Expected '%s', got '%s'.",
-			s.ExpectedRootDevice, image.RootDeviceType))
+			s.ExpectedRootDevice, *image.RootDeviceType))
 		return multistep.ActionHalt
 	}