diff --git a/Project.toml b/Project.toml
index 49e94291..6b1c9edf 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "FastTransforms"
 uuid = "057dd010-8810-581a-b7be-e3fc3b93f78c"
-version = "0.17.2"
+version = "0.17.3"
 
 
 [deps]
diff --git a/src/toeplitzhankel.jl b/src/toeplitzhankel.jl
index 49d44a70..82851112 100644
--- a/src/toeplitzhankel.jl
+++ b/src/toeplitzhankel.jl
@@ -447,13 +447,20 @@ function alternatesign!(v)
     v
 end
 
+# (2k+λ)*Λ(k,λ,μ), using λ*Γ(λ) = Γ(λ+1) for k = 0 to avoid 0*Inf when λ = 0, e.g. when converting to Chebyshev
+function _jac2jac_DL(jk, λ, μ)
+    DL = (2jk .+ λ).*Λ.(jk,λ,μ)
+    isempty(DL) || (DL[1] = Λ(0,λ+1,μ))
+    DL
+end
+
 function _jac2jacTH_TLC(::Type{S}, mn, α, β, γ, δ, d) where {S}
     n = mn[d]
     @assert α+β > -1
     if β == δ
         @assert abs(α-γ) < 1
         jk = 0:n-1
-        DL = (2jk .+ γ .+ β .+ 1).*Λ.(jk,γ+β+1,β+1)
+        DL = _jac2jac_DL(jk,γ+β+1,β+1)
         t = convert(AbstractVector{S}, Λ.(jk, α-γ,1))
         h = Λ.(0:2n-2,α+β+1,γ+β+2)
         DR = Λ.(jk,β+1,α+β+1)./gamma(α-γ)
@@ -462,7 +469,7 @@ function _jac2jacTH_TLC(::Type{S}, mn, α, β, γ, δ, d) where {S}
     elseif α == γ
         @assert abs(β-δ) < 1
         jk = 0:n-1
-        DL = (2jk .+ δ .+ α .+ 1).*Λ.(jk,δ+α+1,α+1)
+        DL = _jac2jac_DL(jk,δ+α+1,α+1)
         h = Λ.(0:2n-2,α+β+1,δ+α+2)
         DR = Λ.(jk,α+1,α+β+1)./gamma(β-δ)
         t = alternatesign!(convert(AbstractVector{S}, Λ.(jk,β-δ,1)))
diff --git a/test/toeplitzhankeltests.jl b/test/toeplitzhankeltests.jl
index f9a9029c..5e4589af 100644
--- a/test/toeplitzhankeltests.jl
+++ b/test/toeplitzhankeltests.jl
@@ -39,6 +39,10 @@ Random.seed!(0)
         @test th_jac2cheb(x, 0.2, 0.3) ≈ jac2cheb(x, 0.2, 0.3)
         @test th_cheb2jac(x, 1, 1) ≈ cheb2jac(x, 1, 1)
         @test th_jac2cheb(x, 1, 1) ≈ jac2cheb(x, 1, 1)
+        # intermediate conversions hit γ+β+1 == 0
+        @test th_jac2cheb(x, -0.25, -0.25) ≈ jac2cheb(x, -0.25, -0.25)
+        @test th_jac2cheb(x, -0.4, -0.1) ≈ jac2cheb(x, -0.4, -0.1)
+        @test th_jac2jac(x, -0.25, -0.25, 0.5, 0.5) ≈ lib_jac2jac(x, -0.25, -0.25, 0.5, 0.5)
 
         @test th_cheb2leg(th_leg2cheb(x)) ≈ x
         @test th_leg2cheb(th_cheb2leg(x)) ≈ x