diff --git a/src/intervals/intervals.jl b/src/intervals/intervals.jl
index 2ae7b0447..3a56f606d 100644
--- a/src/intervals/intervals.jl
+++ b/src/intervals/intervals.jl
@@ -16,7 +16,7 @@ abstract type AbstractInterval{T} <: Real end
 abstract type Behavior end
 struct SetLike <: Behavior end
 struct NumberLike <: Behavior end
-const DefaultBehavior = NumberLike
+const DefaultBehavior = SetLike
 
 struct Interval{T <: Real, B <: Behavior} <: AbstractInterval{T}
     lo :: T