diff --git a/src/api/derivative.jl b/src/api/derivative.jl
index b918f203..1ff285ce 100644
--- a/src/api/derivative.jl
+++ b/src/api/derivative.jl
@@ -35,9 +35,7 @@ end
     end
 end
 
-# The below code generation enables better type inferencing in the event that
-# `f` is a type (see https://github.com/JuliaDiff/ForwardDiff.jl/issues/54).
-closure_deriv_def = quote
+function derivative{A}(f, ::Type{A}=Void; mutates=false)
     if mutates
         d!(output, x::Number) = ForwardDiff.derivative!(output, f, x, A)
         return d!
@@ -46,8 +44,3 @@ closure_deriv_def = quote
         return d
     end
 end
-
-@eval begin
-    derivative{A}(f, ::Type{A}=Void; mutates=false) = $closure_deriv_def
-    derivative{A,f}(::Type{f}, ::Type{A}=Void; mutates=false) = $closure_deriv_def
-end
diff --git a/src/api/jacobian.jl b/src/api/jacobian.jl
index d7f2dddf..39e9e605 100644
--- a/src/api/jacobian.jl
+++ b/src/api/jacobian.jl
@@ -48,8 +48,8 @@ function jacobian{A}(f, ::Type{A}=Void;
     # appropriate closure
     if output_length > 0
         output_cache = ForwardDiffCache()
-        function newf{G<:GradientNumber}(x::Vector{G})
-            output = get_workvec!(output_cache, G, output_length)
+        newf = (x::Vector) -> begin
+            output = get_workvec!(output_cache, eltype(x), output_length)
             f(output, x)
             return output
         end
diff --git a/test/test_behaviors.jl b/test/test_behaviors.jl
index 77ea6bff..53ef2bc5 100644
--- a/test/test_behaviors.jl
+++ b/test/test_behaviors.jl
@@ -53,61 +53,57 @@ j = x -> ForwardDiff.jacobian(g, x, chunk_size=2)/2 # jacobian in chunk_mode
 # Promote type Issues #
 #######################
 
-# Test overloading of `promote_array_type`
-#-------------------------------------------------------#
+# Test overloading of `promote_array_type` #
+#------------------------------------------#
 
 promtyp = Base.promote_array_type(Base.DotAddFun(),
                                   ForwardDiff.ForwardDiffNumber{2, Float64,
                                   Tuple{Float64, Float64}}, Float64)
-fdiffnum = ForwardDiff.ForwardDiffNumber{2,Float64,Tuple{Float64,Float64}}    
+fdiffnum = ForwardDiff.ForwardDiffNumber{2,Float64,Tuple{Float64,Float64}}
 @test promtyp <: fdiffnum
 
 
 promtyp = Base.promote_array_type(Base.DotAddFun(),
                                   ForwardDiff.GradientNumber{2, Float64,
-                                  Tuple{Float64, Float64}}, Float64)    
-gradnum = ForwardDiff.GradientNumber{2,Float64,Tuple{Float64,Float64}}    
+                                  Tuple{Float64, Float64}}, Float64)
+gradnum = ForwardDiff.GradientNumber{2,Float64,Tuple{Float64,Float64}}
 @test promtyp <: gradnum
 
 promtyp = Base.promote_array_type(Base.DotAddFun(),
                                   ForwardDiff.HessianNumber{2, Float64,
-                                  Tuple{Float64, Float64}}, Float64)    
-hessnum = ForwardDiff.HessianNumber{2,Float64,Tuple{Float64,Float64}}    
+                                  Tuple{Float64, Float64}}, Float64)
+hessnum = ForwardDiff.HessianNumber{2,Float64,Tuple{Float64,Float64}}
 @test promtyp <: hessnum
 
 promtyp = Base.promote_array_type(Base.DotAddFun(),
                                   ForwardDiff.TensorNumber{2, Float64,
-                                  Tuple{Float64, Float64}}, Float64)    
-tensnum = ForwardDiff.TensorNumber{2,Float64,Tuple{Float64,Float64}}    
+                                  Tuple{Float64, Float64}}, Float64)
+tensnum = ForwardDiff.TensorNumber{2,Float64,Tuple{Float64,Float64}}
 @test promtyp <: tensnum
 
-    
-# functions involving `.-`, `.+`, etc.                  # 
-#-------------------------------------------------------#
 
-a    = ones(4)
+# Arithmetic element-wise functions #
+#-----------------------------------#
 
-## Test jacobian    
+N = 4
+a = ones(N)
 jac0 = reshape(vcat([[zeros(N*(i-1)); a; zeros(N^2-N*i)] for i = 1:N]...), N^2, N)
 
-for op = [:-, :+, :./, :.*]
-    @eval fn(x) = [($op)(x[1], a); ($op)(x[2], a); ($op)(x[3], a); ($op)(x[4], a)]
-    jac = ForwardDiff.jacobian(fn, a)
+for op in (-, +, .-, .+, ./, .*)
+
+    f = x -> [op(x[1], a); op(x[2], a); op(x[3], a); op(x[4], a)]
+
+    # jacobian
+    jac = ForwardDiff.jacobian(f, a)
     @test reduce(&, -jac + jac0 .== 0)
-end
 
-## Test hessian
-for op = [:-, :+, :./, :.*]
-    @eval fn(x) = sum([($op)(x[1], a); ($op)(x[2], a); ($op)(x[3], a); ($op)(x[4], a)])
-    hess = ForwardDiff.hessian(fn, a)
+    f = x -> sum([op(x[1], a); op(x[2], a); op(x[3], a); op(x[4], a)])
+
+    # hessian
+    hess = ForwardDiff.hessian(f, a)
     @test reduce(&, -hess + zeros(N, N) .== 0)
-end
 
-## Test tensor
-for op = [:-, :+, :./, :.*]
-    @eval fn(x) = sum([($op)(x[1], a); ($op)(x[2], a); ($op)(x[3], a); ($op)(x[4], a)])
-    tens = ForwardDiff.tensor(fn, a)
+    # tensor
+    tens = ForwardDiff.tensor(f, a)
     @test reduce(&, -tens + zeros(N, N, N) .== 0)
 end
-
-
diff --git a/test/test_deprecated.jl b/test/test_deprecated.jl
index d71b1f3d..e42b2ecd 100644
--- a/test/test_deprecated.jl
+++ b/test/test_deprecated.jl
@@ -1,8 +1,8 @@
 T = Float64
 dummy_fsym = :sin
-testexpr = :(sin(a) + exp(b) - tan(c) * cos(d)) 
+testexpr = :(sin(a) + exp(b) - tan(c) * cos(d))
 
-@eval function testf(x::Vector) 
+testf = @eval (x::Vector) -> begin
     a,b,c,d = x
     return $testexpr
 end
@@ -31,7 +31,7 @@ testout = Array(T, M, N)
 testexpr_jac = [:(sin(a) + cos(b)), :(-tan(c)), :(4 * exp(d)), :(cos(b)^5), :(sin(a))]
 testresult = jacob_test_result(testexpr_jac, testx)
 
-@eval function jactestf(x::Vector) 
+jactestf = @eval (x::Vector) -> begin
     a,b,c,d = x
     return [$(testexpr_jac...)]
 end
@@ -49,10 +49,10 @@ jacf = forwarddiff_jacobian(jactestf, T)
 N = 6
 testx = hess_test_x(dummy_fsym, N)
 testout = Array(T, N, N)
-testexpr_hess = :(sin(a) + exp(b) - tan(c) * cos(l) + sin(m) * exp(r)) 
+testexpr_hess = :(sin(a) + exp(b) - tan(c) * cos(l) + sin(m) * exp(r))
 testresult = hess_test_result(testexpr_hess, testx)
 
-@eval function hess_testf(x::Vector) 
+hess_testf = @eval (x::Vector) -> begin
     a,b,c,l,m,r = x
     return $testexpr_hess
 end
diff --git a/test/test_derivatives.jl b/test/test_derivatives.jl
index a1113351..8cdf0fc2 100644
--- a/test/test_derivatives.jl
+++ b/test/test_derivatives.jl
@@ -32,8 +32,8 @@ end
 for fsym in ForwardDiff.auto_defined_unary_funcs
     func_expr = :($(fsym)(x) + 4^$(fsym)(x) - x * $(fsym)(x))
     deriv = Calculus.differentiate(func_expr)
-    try 
-        @eval begin 
+    try
+        @eval begin
             x = deriv_test_x($fsym)
             testdf = x -> $func_expr
             val_result = testdf(x)
diff --git a/test/test_gradients.jl b/test/test_gradients.jl
index e4606226..5f238f03 100644
--- a/test/test_gradients.jl
+++ b/test/test_gradients.jl
@@ -279,7 +279,7 @@ chunk_sizes = (ForwardDiff.default_chunk_size, 1, Int(N/2), N)
 for fsym in map(first, Calculus.symbolic_derivatives_1arg())
     testexpr = :($(fsym)(a) + $(fsym)(b) - $(fsym)(c) * $(fsym)(d))
 
-    @eval function testf(x::Vector)
+    testf = @eval (x::Vector) -> begin
         a,b,c,d = x
         return $testexpr
     end
diff --git a/test/test_hessians.jl b/test/test_hessians.jl
index cf07a5f8..6ede9266 100644
--- a/test/test_hessians.jl
+++ b/test/test_hessians.jl
@@ -268,7 +268,7 @@ chunk_sizes = (ForwardDiff.default_chunk_size, 2, Int(N/2), N)
 for fsym in ForwardDiff.auto_defined_unary_hess_funcs
     testexpr = :($(fsym)(a) + $(fsym)(b) - $(fsym)(c) * $(fsym)(l) - $(fsym)(m) + $(fsym)(r))
 
-    @eval function testf(x::Vector)
+    testf = @eval (x::Vector) -> begin
         a,b,c,l,m,r = x
         return $testexpr
     end
diff --git a/test/test_jacobians.jl b/test/test_jacobians.jl
index ffc70ba6..f9d1834d 100644
--- a/test/test_jacobians.jl
+++ b/test/test_jacobians.jl
@@ -40,12 +40,12 @@ for fsym in ForwardDiff.auto_defined_unary_funcs
                 :($(fsym)(b)^5),
                 :($(fsym)(a))]
 
-    @eval function testf(x::Vector) 
+    testf = @eval (x::Vector) -> begin
         a,b,c,d = x
         return [$(testexprs...)]
     end
 
-    @eval function testf!(output::Vector, x::Vector)
+    testf! = @eval (output::Vector, x::Vector) -> begin
         a,b,c,d = x
         output[1] = $(testexprs[1])
         output[2] = $(testexprs[2])
@@ -59,7 +59,7 @@ for fsym in ForwardDiff.auto_defined_unary_funcs
             testx = jacob_test_x(fsym, N)
             val_result = testf(testx)
             jacob_result = jacob_test_result(testexprs, testx)
-            
+
             # Non-AllResults
             test_jacob = (testout) -> @test_approx_eq testout jacob_result
 
@@ -67,7 +67,7 @@ for fsym in ForwardDiff.auto_defined_unary_funcs
             test_jacob(testout)
 
             test_jacob(ForwardDiff.jacobian(testf, testx; chunk_size=chunk))
-            
+
             jacf! = ForwardDiff.jacobian(testf; mutates=true, chunk_size=chunk)
             testout = similar(testout)
             jacf!(testout, testx)
@@ -123,4 +123,4 @@ for fsym in ForwardDiff.auto_defined_unary_funcs
             throw(err)
         end
     end
-end
\ No newline at end of file
+end
diff --git a/test/test_tensors.jl b/test/test_tensors.jl
index 6ad6ae8c..0d6f608d 100644
--- a/test/test_tensors.jl
+++ b/test/test_tensors.jl
@@ -195,7 +195,7 @@ rand_tens = TensorNumber(rand_hess, rand_tensvec)
 # Multiplication/Division #
 #-------------------------#
 function tens_approx_eq(a::TensorNumber, b::TensorNumber)
-    eps = 1e-9
+    eps = 1e-8
     try
         @test_approx_eq_eps value(a) value(b) eps
         @test_approx_eq_eps collect(grad(a)) collect(grad(b)) eps
@@ -285,7 +285,7 @@ end
 for fsym in ForwardDiff.auto_defined_unary_tens_funcs
     testexpr = :($(fsym)(a) + $(fsym)(b) - $(fsym)(c) * $(fsym)(d))
 
-    @eval function testf(x::Vector)
+    testf = @eval (x::Vector) -> begin
         a,b,c,d = x
         return $testexpr
     end