diff --git a/src/dual.jl b/src/dual.jl
index 2ca4683f..367e1b6a 100644
--- a/src/dual.jl
+++ b/src/dual.jl
@@ -25,6 +25,9 @@ end
 ##########
 Base.ArithmeticStyle(::Type{<:Dual{T,V}}) where {T,V} = Base.ArithmeticStyle(V)
 
+unwrap_dual(::Type{Dual{T,V,N}}) where {T,V,N} = unwrap_dual(V)
+unwrap_dual(::Type{V}) where V = V
+
 ##############
 # Exceptions #
 ##############
diff --git a/src/partials.jl b/src/partials.jl
index a5316e3e..d9d13f98 100644
--- a/src/partials.jl
+++ b/src/partials.jl
@@ -163,7 +163,11 @@ end
 @inline rand_tuple(::AbstractRNG, ::Type{Tuple{}}) = tuple()
 @inline rand_tuple(::Type{Tuple{}}) = tuple()
 
-@generated function iszero_tuple(tup::NTuple{N,V}) where {N,V}
+iszero_tuple(tup::NTuple{N,V}) where {N,V} = _iszero_tuple(unwrap_dual(V), tup)
+
+# default implementation; specific number types (e.g., Interval from IntervalArithmetic)
+# can add specializations.
+@generated function _iszero_tuple(::Type{V0}, tup::NTuple{N,V}) where {V0,N,V}
     ex = Expr(:&&, [:(z == tup[$i]) for i=1:N]...)
     return quote
         z = zero(V)