diff --git a/js/scripts/prop-types.js b/js/scripts/prop-types.js
index 2df6fd22..057f81d5 100644
--- a/js/scripts/prop-types.js
+++ b/js/scripts/prop-types.js
@@ -448,7 +448,7 @@ class UniformDict extends DictType {
         const nullableStr = this.getNullableStr();
         return `Dict(default_value=${
             this.getPythonDefaultValue()
-        }, trait=Uniform(allow_none=True), ${
+        }, value_trait=Uniform(allow_none=True), ${
             nullableStr
         })${this.getTagString()}`;
     }
diff --git a/pythreejs/traits.py b/pythreejs/traits.py
index d35dae8b..4be1710e 100644
--- a/pythreejs/traits.py
+++ b/pythreejs/traits.py
@@ -266,7 +266,7 @@ class Uniform(Dict):
     """A dict holding uniforms for a ShaderMaterial"""
 
     def __init__(self, default_value=Undefined, **kwargs):
-        super(Uniform, self).__init__(traits=dict(
+        super(Uniform, self).__init__(per_key_traits=dict(
             value=Union((
                 Int(), Float(), Color(), Instance('pythreejs.Texture'),
                 List(trait=Union((