diff --git a/Project.toml b/Project.toml
index 7b2b86f..3e04da3 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "Roots"
 uuid = "f2b01f46-fcfa-551c-844a-d8ac1e96c665"
-version = "2.0.17"
+version = "2.0.18"
 
 [deps]
 ChainRulesCore = "d360d2e6-b24c-11e9-a2a3-2a2ae2dbcce4"
diff --git a/src/Bracketing/alefeld_potra_shi.jl b/src/Bracketing/alefeld_potra_shi.jl
index 4df7424..97f787d 100644
--- a/src/Bracketing/alefeld_potra_shi.jl
+++ b/src/Bracketing/alefeld_potra_shi.jl
@@ -46,8 +46,8 @@ end
 # set d, ee to a
 function init_state(::AbstractAlefeldPotraShi, F, x₀, x₁, fx₀, fx₁; c=nothing, fc=nothing)
     a, b, fa, fb = x₀, x₁, fx₀, fx₁
-    iszero(fa) && return AbstractAlefeldPotraShiState(b, a, a, a, fb, fa, fa, fa)
-    iszero(fb) && return AbstractAlefeldPotraShiState(b, a, a, a, fb, fa, fa, fa)
+    iszero(fa) && return AbstractAlefeldPotraShiState(promote(b, a, a, a)..., promote(fb, fa, fa, fa)...)
+    iszero(fb) && return AbstractAlefeldPotraShiState(promote(b, a, a, a)..., promote(fb, fa, fa, fa)...)
 
     if a > b
         a, b, fa, fb = b, a, fb, fa
@@ -59,7 +59,7 @@ function init_state(::AbstractAlefeldPotraShi, F, x₀, x₁, fx₀, fx₁; c=no
     end
 
     (iszero(fc) || !isfinite(fc)) &&
-        return AbstractAlefeldPotraShiState(c, a, a, a, fc, fa, fa, fa)
+        return AbstractAlefeldPotraShiState(promote(c, a, a, a)..., promote(fc, fa, fa, fa)...)
 
     a, b, d, fa, fb, fd = bracket(a, b, c, fa, fb, fc)
     assert_bracket(fa, fb)
diff --git a/src/Bracketing/bisection.jl b/src/Bracketing/bisection.jl
index 514492f..5b98acd 100644
--- a/src/Bracketing/bisection.jl
+++ b/src/Bracketing/bisection.jl
@@ -46,7 +46,7 @@ function init_state(
     end
 
     # handle interval if fa*fb ≥ 0 (explicit, but also not needed)
-    (iszero(fx₀) || iszero(fx₁)) && return UnivariateZeroState(x₁, x₀, fx₁, fx₀)
+    (iszero(fx₀) || iszero(fx₁)) && return UnivariateZeroState(promote(x₁, x₀)..., promote(fx₁, fx₀)...)
     assert_bracket(fx₀, fx₁)
     if sign(fm) * fx₀ < 0 * oneunit(fx₀)
         a, b, fa, fb = x₀, m, fx₀, fm
@@ -57,7 +57,7 @@ function init_state(
     # handles case where a=-0.0, b=1.0 without error
     sign(a) * sign(b) < 0 && throw(ArgumentError("_middle error"))
 
-    UnivariateZeroState(b, a, fb, fa)
+    UnivariateZeroState(promote(b, a)..., promote(fb, fa)...)
 end
 
 const FloatNN = Union{Float64,Float32,Float16}
diff --git a/src/Bracketing/bracketing.jl b/src/Bracketing/bracketing.jl
index 3277a81..3299743 100644
--- a/src/Bracketing/bracketing.jl
+++ b/src/Bracketing/bracketing.jl
@@ -10,7 +10,7 @@ function init_state(M::AbstractBracketingMethod, F, x₀, x₁, fx₀, fx₁)
     (iszero(fx₀) || iszero(fx₁)) && return UnivariateZeroState(x₁, x₀, fx₁, fx₀)
     assert_bracket(fx₀, fx₁)
     a, b, fa, fb = (x₀ < x₁) ? (x₀, x₁, fx₀, fx₁) : (x₁, x₀, fx₁, fx₀)
-    UnivariateZeroState(b, a, fb, fa)
+    UnivariateZeroState(promote(b, a)..., promote(fb, fa)...)
 end
 
 Base.last(state::AbstractUnivariateZeroState, M::AbstractBracketingMethod) =
diff --git a/src/Bracketing/brent.jl b/src/Bracketing/brent.jl
index 9124f91..91b4e33 100644
--- a/src/Bracketing/brent.jl
+++ b/src/Bracketing/brent.jl
@@ -29,10 +29,10 @@ function init_state(::Brent, F, x₀, x₁, fx₀, fx₁)
     end
 
     # check if fu*fv ≥ 0
-    (iszero(fu) || iszero(fv)) && return BrentState(u, v, v, v, fu, fv, fv, true)
+    (iszero(fu) || iszero(fv)) && return BrentState(promote(u, v, v, v)..., promote(fu, fv, fv)..., true)
     assert_bracket(fu, fv)
 
-    BrentState(u, v, v, v, fu, fv, fv, true)
+    BrentState(promote(u, v, v, v)..., promote(fu, fv, fv)..., true)
 end
 
 function update_state(
diff --git a/src/Bracketing/chandrapatlu.jl b/src/Bracketing/chandrapatlu.jl
index 2e83ed3..a36d4a6 100644
--- a/src/Bracketing/chandrapatlu.jl
+++ b/src/Bracketing/chandrapatlu.jl
@@ -25,7 +25,7 @@ end
 function init_state(::Chandrapatla, F, x₀, x₁, fx₀, fx₁)
     a, b, fa, fb = x₁, x₀, fx₁, fx₀
     c, fc = a, fa
-    ChandrapatlaState(a, b, c, fa, fb, fc)
+    ChandrapatlaState(promote(a, b, c)..., promote(fa, fb, fc)...)
 end
 
 function update_state(
diff --git a/src/Bracketing/itp.jl b/src/Bracketing/itp.jl
index 49645dc..b67ce2d 100644
--- a/src/Bracketing/itp.jl
+++ b/src/Bracketing/itp.jl
@@ -58,12 +58,12 @@ function init_state(M::ITP, F, x₀, x₁, fx₀, fx₁)
     ϵ2n₁₂ = zero(float(x₁) / x₁) # ϵ*2^(ceil(Int, log2((b-a)/(2*ϵ))) + n₀)
 
     # handle interval if fa*fb ≥ 0 (explicit, but also not needed)
-    (iszero(fx₀) || iszero(fx₁)) && return ITPState(x₁, x₀, fx₁, fx₀, 0, ϵ2n₁₂, x₁)
+    (iszero(fx₀) || iszero(fx₁)) && return ITPState(promote(x₁, x₀)..., promote(fx₁, fx₀)..., 0, ϵ2n₁₂, x₁)
     assert_bracket(fx₀, fx₁)
 
     a, b, fa, fb = x₀, x₁, fx₀, fx₁
 
-    ITPState(b, a, fb, fa, 0, ϵ2n₁₂, a)
+    ITPState(promote(b, a)..., promote(fb, fa)..., 0, ϵ2n₁₂, a)
 end
 
 function update_state(M::ITP, F, o::ITPState{T,S,R}, options, l=NullTracks()) where {T,S,R}
diff --git a/src/Derivative/halley_like.jl b/src/Derivative/halley_like.jl
index 3b7778c..bea0542 100644
--- a/src/Derivative/halley_like.jl
+++ b/src/Derivative/halley_like.jl
@@ -19,7 +19,7 @@ end
 
 function init_state(::AbstractHalleyLikeMethod, F, x₀::T, x₁::T, fx₀, fx₁) where {T}
     fx₁, (Δ::T, ΔΔ::T) = F(x₁)
-    HalleyState(x₁, x₀, Δ, ΔΔ, fx₁, fx₀)
+    HalleyState(promote(x₁, x₀)..., Δ, ΔΔ, promote(fx₁, fx₀)...)
 end
 
 initial_fncalls(M::AbstractHalleyLikeMethod) = 2 * 3
diff --git a/src/Derivative/newton.jl b/src/Derivative/newton.jl
index 16afeff..f20a81d 100644
--- a/src/Derivative/newton.jl
+++ b/src/Derivative/newton.jl
@@ -66,7 +66,7 @@ end
 # compute fx₁, Δ
 function init_state(::Newton, F, x₀::T, x₁::T, fx₀, fx₁) where {T}
     fx₁, Δ::T = F(x₁)
-    NewtonState(x₁, x₀, Δ, fx₁, fx₀)
+    NewtonState(promote(x₁, x₀)..., Δ, promote(fx₁, fx₀)...)
 end
 
 initial_fncalls(M::Newton) = 2
diff --git a/src/Derivative/thukralb.jl b/src/Derivative/thukralb.jl
index ab8244b..02617e6 100644
--- a/src/Derivative/thukralb.jl
+++ b/src/Derivative/thukralb.jl
@@ -66,7 +66,7 @@ function init_state(
     fx₁;
     Δs=nothing,
 ) where {T}
-    ThukralBState(x₁, x₀, NTuple{fn_argout(M) - 1,T}(Δs), fx₁, fx₀)
+    ThukralBState(promote(x₁, x₀)..., NTuple{fn_argout(M) - 1,T}(Δs), promote(fx₁, fx₀)...)
 end
 
 function update_state(
diff --git a/src/DerivativeFree/derivative_free.jl b/src/DerivativeFree/derivative_free.jl
index 1960dd6..39107f3 100644
--- a/src/DerivativeFree/derivative_free.jl
+++ b/src/DerivativeFree/derivative_free.jl
@@ -9,7 +9,7 @@ end
 
 # initialize from xs, fxs
 function init_state(::AbstractSecantMethod, F, x₀, x₁, fx₀, fx₁)
-    UnivariateZeroState(x₁, x₀, fx₁, fx₀)
+    UnivariateZeroState(promote(x₁, x₀)..., promote(fx₁, fx₀)...)
 end
 
 initial_fncalls(::AbstractSecantMethod) = 2
diff --git a/src/DerivativeFree/king.jl b/src/DerivativeFree/king.jl
index 7e63018..fa7e105 100644
--- a/src/DerivativeFree/king.jl
+++ b/src/DerivativeFree/king.jl
@@ -28,7 +28,7 @@ end
 function init_state(::Union{King,Order1B}, F, x₀, x₁, fx₀, fx₁)
     fₛ₀ = F(x₀ - fx₀ * oneunit(x₀) / oneunit(fx₀))
     G₀ = -fx₀^2 / (fₛ₀ - fx₀)
-    KingState(x₁, x₀, fx₁, fx₀, G₀)
+    KingState(promote(x₁, x₀)..., promote(fx₁, fx₀, G₀)...)
 end
 initial_fncalls(::Union{King,Order1B}) = 3