diff --git a/.gitignore b/.gitignore
index 721a6b78..3e8794f2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
+.vscode
 *.swp
 *.jl.cov
 *.jl.*.cov
diff --git a/Project.toml b/Project.toml
index 427a1a11..7ca2e139 100644
--- a/Project.toml
+++ b/Project.toml
@@ -17,6 +17,7 @@ Requires = "0.5.0, 1"
 julia = "1"
 
 [extras]
+Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
 QuadGK = "1fd47b50-473d-5c70-9696-f719f8f3bcdc"
 SpecialFunctions = "276daf66-3868-5448-9aa4-cd146d93841b"
 Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
@@ -24,4 +25,4 @@ Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 Unitful = "1986cc42-f94f-5a68-af5c-568840ba703d"
 
 [targets]
-test = ["QuadGK", "SpecialFunctions", "Statistics", "Test", "Unitful"]
+test = ["Aqua", "QuadGK", "SpecialFunctions", "Statistics", "Test", "Unitful"]
diff --git a/README.md b/README.md
index b7915cfe..75384b6a 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,8 @@
 # Measurements.jl
 
-| **Documentation**                       | **Build Status**                    | **Code Coverage**               |
-|:---------------------------------------:|:-----------------------------------:|:-------------------------------:|
-| [![][docs-stable-img]][docs-stable-url] | [![Build Status][gha-img]][gha-url] | [![][coveral-img]][coveral-url] |
+| **Documentation**                       | **Build Status**                    | **Code Coverage**               | **Quality** |
+|:---------------------------------------:|:-----------------------------------:|:-------------------------------:|:-----------:|
+| [![][docs-stable-img]][docs-stable-url] | [![Build Status][gha-img]][gha-url] | [![][coveral-img]][coveral-url] |[![Aqua QA][aqua-img]](aqua-url)|
 | [![][docs-latest-img]][docs-latest-url] |                                     | [![][codecov-img]][codecov-url] |
 
 Introduction
@@ -219,3 +219,6 @@ is provided in the [`CITATION.bib`](CITATION.bib) file.
 
 [codecov-img]: https://codecov.io/gh/JuliaPhysics/Measurements.jl/branch/master/graph/badge.svg
 [codecov-url]: https://codecov.io/gh/JuliaPhysics/Measurements.jl
+
+[aqua-img]: https://raw.githubusercontent.com/JuliaTesting/Aqua.jl/master/badge.svg
+[aqua-url]: https://github.com/JuliaTesting/Aqua.jl
\ No newline at end of file
diff --git a/src/Measurements.jl b/src/Measurements.jl
index 83e31ea6..2087fbf6 100644
--- a/src/Measurements.jl
+++ b/src/Measurements.jl
@@ -60,8 +60,18 @@ function Measurement(val::V, err::E, tag::UInt64,
     return Measurement(T(val), T(err), tag, Derivatives{T}(der))
 end
 Measurement{T}(x::Measurement{S}) where {T,S} = convert(Measurement{T}, x)
-Measurement{T}(x::S) where {T,S} = convert(Measurement{T}, x)
-Measurement{T}(x::S) where {T,S<:Rational} = convert(Measurement{T}, x)
+Measurement{T}(x::S) where {T,S <: Real} = convert(Measurement{T}, x)
+
+# disambiguities
+Measurement{T}(x::S) where {T, S<:Rational} = convert(Measurement{T}, x)
+Measurement{T}(x::S) where {T, S<:Complex} = convert(Measurement{T}, x)
+Measurement{T}(x::S) where {T, S<:Base.TwicePrecision} = convert(Measurement{T}, x)
+Measurement{T}(x::S) where {P, T, S<:Rational{P}} = convert(Measurement{T}, x)
+Measurement{T}(x::S) where {T, S <: AbstractChar} = convert(Measurement{T}, x)
+
+function Measurement{T}(::S) where {T, S}
+    throw(ArgumentError("cannot convert `$S` to `Measurement{$T}`"))
+end
 
 # Functions to quickly create an empty Derivatives object.
 @generated empty_der1(x::Measurement{T}) where {T<:AbstractFloat} = Derivatives{T}()
diff --git a/src/comparisons-tests.jl b/src/comparisons-tests.jl
index d673052b..eb7a04d8 100644
--- a/src/comparisons-tests.jl
+++ b/src/comparisons-tests.jl
@@ -25,9 +25,11 @@ Base.:(==)(a::Measurement, b::Measurement) = (a.val==b.val && a.err==b.err)
 Base.:(==)(a::Measurement, b::Irrational) = false
 Base.:(==)(a::Measurement, b::Rational) = (a.val==b && iszero(a.err))
 Base.:(==)(a::Measurement, b::Real) = (a.val==b && iszero(a.err))
+Base.:(==)(a::Measurement, b::AbstractIrrational) = (a.val==b && iszero(b.err))
 Base.:(==)(a::Irrational, b::Measurement) = false
 Base.:(==)(a::Rational, b::Measurement) = (a==b.val && iszero(b.err))
 Base.:(==)(a::Real, b::Measurement) = (a==b.val && iszero(b.err))
+Base.:(==)(a::AbstractIrrational, b::Measurement) = (a==b.val && iszero(b.err))
 
 # Create a hashing function that matches the same behaviour as `==`: only the
 # `val` and `err` fields matter.
@@ -39,8 +41,10 @@ for cmp in (:<, :<=)
         Base.$cmp(a::Measurement, b::Measurement) = ($cmp)(a.val, b.val)
         Base.$cmp(a::Measurement, b::Rational) = ($cmp)(a.val, b)
         Base.$cmp(a::Measurement, b::Real) = ($cmp)(a.val, b)
+        Base.$cmp(a::Measurement, b::AbstractIrrational) = ($cmp)(a.val, b)
         Base.$cmp(a::Rational, b::Measurement) = ($cmp)(a, b.val)
         Base.$cmp(a::Real, b::Measurement) = ($cmp)(a, b.val)
+        Base.$cmp(a::AbstractIrrational, b::Measurement) = ($cmp)(a, b.val)
     end
 end
 
diff --git a/src/conversions.jl b/src/conversions.jl
index 499204d8..753ebfbe 100644
--- a/src/conversions.jl
+++ b/src/conversions.jl
@@ -22,6 +22,18 @@ Base.convert(::Type{Measurement{T}}, a::Rational{<:Integer}) where {T<:AbstractF
     measurement(T(a))::Measurement{T}
 Base.convert(::Type{Measurement{T}}, a::Real) where {T<:AbstractFloat} =
     measurement(T(a))::Measurement{T}
+Base.convert(::Type{Measurement{T}}, a::Base.TwicePrecision) where {T<:AbstractFloat} =
+    measurement(T(a))::Measurement{T}
+Base.convert(::Type{Measurement{T}}, a::AbstractChar) where {T<:AbstractFloat} =
+    measurement(T(a))::Measurement{T}
+
+function Base.convert(::Type{Measurement{T}}, a::Complex) where {T}
+    if isreal(a)
+        measurement(T(real(a)))
+    else
+        throw(InexactError(:convert, Measurement{T}, a))
+    end
+end
 
 Base.convert(::Type{Measurement{T}}, a::Measurement{T}) where {T<:AbstractFloat} = a
 function Base.convert(::Type{Measurement{T}},
diff --git a/src/math.jl b/src/math.jl
index f6ca9c96..4bb1284b 100644
--- a/src/math.jl
+++ b/src/math.jl
@@ -56,7 +56,7 @@ end
 # Get the common type parameter of a collection of Measurement objects.  The first two
 # methods are for the trivial cases of homogeneous tuples and arrays, the last, inefficient,
 # method is for inhomogeneous collections (probably the least common case).
-gettype(::Tuple{Vararg{Measurement{T}}}) where {T<:AbstractFloat} = T
+gettype(::Tuple{Measurement{T}, Vararg{Measurement{T}}}) where {T<:AbstractFloat} = T
 gettype(::AbstractArray{Measurement{T}}) where {T<:AbstractFloat} = T
 _eltype(::Measurement{T}) where {T<:AbstractFloat} = T
 gettype(collection) = promote_type(_eltype.(collection)...)
@@ -174,6 +174,7 @@ end
 # Addition: +
 Base.:+(a::Measurement, b::Measurement) = result(a.val + b.val, (1, 1), (a, b))
 Base.:+(a::Real, b::Measurement) = result(a + b.val, 1, b)
+Base.:+(a::Bool, b::Measurement) = result(a + b.val, 1, b)
 Base.:+(a::Measurement, b::Bool) = result(a.val + b, 1, a)
 Base.:+(a::Measurement, b::Real) = result(a.val + b, 1, a)
 
@@ -685,9 +686,12 @@ Base.sign(a::Measurement) = result(sign(a.val), 0, a)
 
 Base.copysign(a::Measurement, b::Measurement) = ifelse(signbit(a)!=signbit(b), -a, a)
 Base.copysign(a::Measurement, b::Real)        = ifelse(signbit(a)!=signbit(b), -a, a)
+Base.copysign(a::Measurement, b::Unsigned)    = ifelse(signbit(a)!=signbit(b), -a, a)
+
 Base.flipsign(a::Measurement, b::Measurement) = ifelse(signbit(b), -a, a)
 Base.flipsign(a::Measurement, b::Real)        = ifelse(signbit(b), -a, a)
-for T in (Signed, Rational, Float32, Float64, Real)
+Base.flipsign(a::Measurement, b::Unsigned)    = ifelse(signbit(b), -a, a)
+for T in (Signed, Unsigned, Rational, Float32, Float64, Real)
     @eval Base.copysign(a::$T, b::Measurement) = copysign(a, b.val)
     @eval Base.flipsign(a::$T, b::Measurement) = flipsign(a, b.val)
 end
@@ -734,6 +738,15 @@ Base.round(a::Measurement, r::RoundingMode=RoundNearest; kwargs...) =
     measurement(round(value(a), r; kwargs...), round(uncertainty(a); kwargs...))
 Base.round(::Type{T}, a::Measurement, r::RoundingMode=RoundNearest) where {T<:Integer} =
     round(T, a.val, r)
+
+# disambiguities
+Base.round(a::Measurement, r::RoundingMode{:NearestTiesAway}; kwargs...) =
+    measurement(round(value(a), r; kwargs...), round(uncertainty(a), r; kwargs...))
+Base.round(a::Measurement, r::RoundingMode{:NearestTiesUp}; kwargs...) =
+    measurement(round(value(a), r; kwargs...), round(uncertainty(a), r; kwargs...))
+Base.round(::Type{T}, a::Measurement, r::RoundingMode{:ToZero}) where {T<:Integer} =
+    measurement(round(T, value(a), r), round(uncertainty(a), r))
+
 Base.floor(a::Measurement) = measurement(floor(a.val))
 Base.floor(::Type{T}, a::Measurement) where {T<:Integer} = floor(T, a.val)
 Base.ceil(a::Measurement) = measurement(ceil(a.val))
diff --git a/test/runtests.jl b/test/runtests.jl
index 73449029..2f26993a 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -1,5 +1,6 @@
 using Measurements, SpecialFunctions, QuadGK, Calculus
-using Test, LinearAlgebra, Statistics, Unitful, Printf
+using Test, LinearAlgebra, Statistics, Unitful, Printf, Aqua
+Aqua.test_all(Measurements)
 
 import Base: isapprox
 import Measurements: value, uncertainty
@@ -46,6 +47,14 @@ end
     @test x != pi != y
 end
 
+@testset "constructors" begin
+    @test Measurement{Float64}(1.0 + 0im) ≈ 1.0 ± 0.0
+    @test Measurement{Float64}(1//2) ≈ 0.5 ± 0.0
+    @test Measurement{Float64}((1:1e-2:2).step) ≈ 1e-2±0.0
+    @test Measurement{Float64}('a') ≈ Float64('a') ± 0.0
+    @test_throws ArgumentError Measurement{Float64}("aaa")
+end
+
 @testset "missing values" begin
     @test measurement(missing) === missing
     @test measurement(missing, .1) === missing
@@ -104,6 +113,11 @@ end
         Measurement{Float64}
     @test promote_type(Measurement{BigFloat}, Measurement{Float64}) ==
         Measurement{BigFloat}
+
+    @test convert(Measurement{Float64}, 1+0im) ≈ 1.0±0.0
+    @test_throws InexactError convert(Measurement{Float64}, 1+1im)
+    @test convert(Measurement{Float64}, Base.TwicePrecision(1.0, 0.0)) ≈ 1.0±0.0
+    @test convert(Measurement{Float64}, 'a') ≈ Float64('a') ± 0.0
 end
 
 @testset "Comparisons and Tests" begin
@@ -136,6 +150,8 @@ end
     @test isone(one(Measurement))
     @test !isone(1 ± 1)
     @test !isone(0 ± 0)
+    @test 1//2 ± 0.0 == 1//2
+    @test 1//2 == 1//2 ± 0.0
 end
 
 @testset "Hashing and dictionaries" begin
@@ -562,6 +578,9 @@ end
         @test @inferred(rem2pi(a, r)) ≈ rem(a, 2pi, r)
         @test rem2pi(a, r) ≈ a - 2pi * round(a / (2pi), r)
     end
+
+    @test round(3.141234±0.1, RoundNearestTiesAway) ≈ 3.0±0.0
+    @test round(3.141234±0.1, RoundNearestTiesUp) ≈ 3.0±0.0
 end
 
 @testset "Machine precision" begin