diff --git a/Project.toml b/Project.toml
index 06047b46..38f2b294 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "MLJBase"
 uuid = "a7f614a8-145f-11e9-1d2a-a57a1082229d"
 authors = ["Anthony D. Blaom <anthony.blaom@gmail.com>"]
-version = "0.15.5"
+version = "0.15.6"
 
 [deps]
 CategoricalArrays = "324d7699-5711-5eae-9e2f-1d82baa6b597"
@@ -33,7 +33,7 @@ Tables = "bd369af6-aec1-5ad0-b16a-f7cc5008161c"
 CategoricalArrays = "^0.8.1"
 ComputationalResources = "^0.3"
 Distributions = "0.22, 0.23, 0.24"
-HTTP = "^0.8"
+HTTP = "^0.8, 0.9"
 InvertedIndices = "^1"
 JLSO = "^2.1,^2.2"
 JSON = "^0.21"
@@ -43,7 +43,7 @@ MLJScientificTypes = "^0.3"
 Missings = "^0.4"
 OrderedCollections = "^1.1"
 Parameters = "^0.12"
-PrettyTables = "^0.8,^0.9"
+PrettyTables = "^0.8,^0.9, 0.10"
 ProgressMeter = "^1.3"
 StatsBase = "^0.32,^0.33"
 Tables = "^0.2,^1.0"
diff --git a/src/hyperparam/one_dimensional_ranges.jl b/src/hyperparam/one_dimensional_ranges.jl
index bc1801a0..dfbfddf6 100644
--- a/src/hyperparam/one_dimensional_ranges.jl
+++ b/src/hyperparam/one_dimensional_ranges.jl
@@ -174,7 +174,7 @@ nominal_range(T, field, ::Nothing) = throw(ArgumentError(
 "the example, "*
 "`range(Int, :dummy, lower=1, upper=10)`. "  ))
 
-function nominal_range(::Type{T}, field, values::AbstractVector{T}) where T
+function nominal_range(::Type{T}, field, values::AbstractVector{<:T}) where T
     return NominalRange{T,length(values)}(field, Tuple(values))
 end
 
diff --git a/src/machines.jl b/src/machines.jl
index 2e252417..3ff25399 100644
--- a/src/machines.jl
+++ b/src/machines.jl
@@ -430,7 +430,7 @@ function fit_only!(mach::Machine; rows=nothing, verbosity=1, force=false)
                 @info "Running type checks... "
                 check(mach.model, source.(raw_args)... ; full=true) &&
                     @info "Type checks okay. "
-                rethrow(exception)
+                rethrow()
             end
     elseif mach.model != mach.old_model
         # update the model: