diff --git a/base/floatfuncs.jl b/base/floatfuncs.jl
index dbaa8b924da17..941318da37b6f 100644
--- a/base/floatfuncs.jl
+++ b/base/floatfuncs.jl
@@ -176,7 +176,7 @@ const ≈ = isapprox
 # default tolerance arguments
 rtoldefault{T<:AbstractFloat}(::Type{T}) = sqrt(eps(T))
 rtoldefault{T<:Real}(::Type{T}) = 0
-rtoldefault{T<:Number,S<:Number}(x::Union{T,Type{T}}, y::Union{S,Type{S}}) = rtoldefault(promote_type(real(T),real(S)))
+rtoldefault{T<:Number,S<:Number}(x::Union{T,Type{T}}, y::Union{S,Type{S}}) = max(rtoldefault(real(T)),rtoldefault(real(S)))
 
 # fused multiply-add
 fma_libm(x::Float32, y::Float32, z::Float32) =
diff --git a/test/numbers.jl b/test/numbers.jl
index f108f6410641a..a96cb373dfe6f 100644
--- a/test/numbers.jl
+++ b/test/numbers.jl
@@ -1663,10 +1663,10 @@ end
 @test isnan(eps(-Inf))
 
 @test .1+.1+.1 != .3
-# TODO: uncomment when isapprox() becomes part of base.
-# @test isapprox(.1+.1+.1, .3)
-# @test !isapprox(.1+.1+.1-.3, 0)
-# @test isapprox(.1+.1+.1-.3, 0, eps(.3))
+@test isapprox(.1+.1+.1, .3)
+@test !isapprox(.1+.1+.1-.3, 0)
+@test isapprox(.1+.1+.1-.3, 0, atol=eps(.3))
+@test isapprox(1.1,1.1f0)
 
 @test div(1e50,1) == 1e50
 @test fld(1e50,1) == 1e50