diff --git a/ext/IntervalArithmeticForwardDiffExt.jl b/ext/IntervalArithmeticForwardDiffExt.jl
index 869d926e..520ff828 100644
--- a/ext/IntervalArithmeticForwardDiffExt.jl
+++ b/ext/IntervalArithmeticForwardDiffExt.jl
@@ -5,13 +5,16 @@ using ForwardDiff: Dual, ≺, value, partials
 
 # Needed to avoid method ambiguities:
 Base.promote_rule(::Type{Dual{T, V, N}}, ::Type{Interval{S}}) where {T, V, N, S<:Union{AbstractFloat, Rational}} =
-    Interval{IntervalArithmetic.promote_numtype(V, S)}
+    Dual{T,Interval{IntervalArithmetic.promote_numtype(V, S)},N}
+
+Base.promote_rule(::Type{Interval{S}}, ::Type{ForwardDiff.Dual{T, V, N}}) where {S<:Union{AbstractFloat, Rational}, T, V, N} =
+    Dual{T,Interval{IntervalArithmetic.promote_numtype(V, S)},N}
 
 Base.promote_rule(::Type{ExactReal{S}}, ::Type{Dual{T, V, N}}) where {S<:Real, T, V, N} =
-    ExactReal{IntervalArithmetic.promote_numtype(V, S)}
+    Dual{T,ExactReal{IntervalArithmetic.promote_numtype(V, S)},N}
 
 Base.promote_rule(::Type{Dual{T, V, N}}, ::Type{ExactReal{S}}) where {S<:Real, T, V, N} =
-    ExactReal{IntervalArithmetic.promote_numtype(V, S)}
+    Dual{T,ExactReal{IntervalArithmetic.promote_numtype(V, S)},N}
 
 Base.:(==)(x::Union{BareInterval,Interval}, y::Dual) = isthin(x, y)
 Base.:(==)(x::Dual, y::Union{BareInterval,Interval}) = y == x