diff --git a/invoke/vendor/yaml/constructor.py b/invoke/vendor/yaml/constructor.py
index 619acd307..733c329be 100644
--- a/invoke/vendor/yaml/constructor.py
+++ b/invoke/vendor/yaml/constructor.py
@@ -413,6 +413,10 @@ def construct_yaml_map(self, node):
         value = self.construct_mapping(node)
         data.update(value)
 
+    def construct_yaml_join(self, node):
+        seq = self.construct_sequence(node)
+        return ''.join([str(i) for i in seq])
+
     def construct_yaml_object(self, node, cls):
         data = cls.__new__(cls)
         yield data
@@ -476,6 +480,10 @@ def construct_undefined(self, node):
         'tag:yaml.org,2002:map',
         SafeConstructor.construct_yaml_map)
 
+SafeConstructor.add_constructor(
+        '!join',
+        SafeConstructor.construct_yaml_join)
+
 SafeConstructor.add_constructor(None,
         SafeConstructor.construct_undefined)