diff --git a/libraries/nprlib/nprlib_defs.mtlx b/libraries/nprlib/nprlib_defs.mtlx
index cfb0c023b0..31bbfea3ac 100644
--- a/libraries/nprlib/nprlib_defs.mtlx
+++ b/libraries/nprlib/nprlib_defs.mtlx
@@ -47,7 +47,7 @@
     <input name="warm_color" type="color3" value="0.8, 0.8, 0.7" uiname="Warm Color" doc="Warm color" />
     <input name="cool_color" type="color3" value="0.3, 0.3, 0.8" uiname="Cool Color" doc="Cool color" />
     <input name="specular_intensity" type="float" value="1" uimin="0" uimax="1" uiname="Specular Intensity" doc="Specular Intensity" />
-    <input name="shininess" type="float" value="64" uimin="1" uimax="64" uiname="Shininess" doc="Specular Power" />
+    <input name="shininess" type="float" value="64" uimin="1" uisoftmax="64" uiname="Shininess" doc="Specular Power" />
     <input name="light_direction" type="vector3" value="1, -0.5, -0.5" uiname="Light Direction" doc="Light vector in world space" />
     <output name="out" type="color3"/>
   </nodedef>