diff --git a/tests/test_ec2/test_elastic_block_store.py b/tests/test_ec2/test_elastic_block_store.py
index ac9c7e3d..4bd2a8df 100644
--- a/tests/test_ec2/test_elastic_block_store.py
+++ b/tests/test_ec2/test_elastic_block_store.py
@@ -77,7 +77,7 @@ def test_delete_attached_volume():
     ex.exception.error_code.should.equal("VolumeInUse")
     ex.exception.status.should.equal(400)
     ex.exception.message.should.equal(
-        f"Volume {volume.id} is currently attached to {instance.id}"
+        "Volume {0} is currently attached to {1}".format(volume.id, instance.id)
     )
 
     volume.detach()