diff --git a/src/optimise/optimisers.jl b/src/optimise/optimisers.jl
index 569e69aa..29b058ba 100644
--- a/src/optimise/optimisers.jl
+++ b/src/optimise/optimisers.jl
@@ -64,11 +64,11 @@ end
 
 function adamax(p::Param; η::Real = 0.002, β1::Real = 0.9, β2::Real = 0.999, ϵ::Real = 1e-8)
   mt = zeros(p.x)
-  ut = zero(p.x)
+  ut = zeros(p.x)
   β1p = β1
   function ()
     @. mt = β1 * mt + (1 - β1) * p.Δ
-    ut = max(β2 * ut, norm(p.Δ, Inf))
+    @. ut = max(β2 * ut, abs(p.Δ))
     @. p.Δ = (η/(1 - β1p)) * mt/(ut + ϵ)
     β1p *= β1
   end