diff --git a/src/Arrays/SingleEntryVector.jl b/src/Arrays/SingleEntryVector.jl
index 607063dec4..aefad6b33d 100644
--- a/src/Arrays/SingleEntryVector.jl
+++ b/src/Arrays/SingleEntryVector.jl
@@ -37,12 +37,17 @@ function Base.:(*)(A::Transpose{N, <:AbstractMatrix{N}},
     return A[:, e.i] * e.v
 end
 
-# diagonal matrix times unit vector
+# multiplication with diagonal matrix
 function Base.:(*)(D::Diagonal{N, V},
                    e::SingleEntryVector{N}) where {N, V<:AbstractVector{N}}
     return SingleEntryVector(e.i, e.n, D.diag[e.i] * e.v)
 end
 
+# negation
+function Base.:(-)(e::SingleEntryVector{N}) where {N}
+    return SingleEntryVector(e.i, e.n, -e.v)
+end
+
 function inner(e1::SingleEntryVector{N}, A::AbstractMatrix{N},
                e2::SingleEntryVector{N}) where {N}
     return A[e1.i, e2.i] * e1.v * e2.v
diff --git a/src/Translation.jl b/src/Translation.jl
index 094871183a..645e5012c1 100644
--- a/src/Translation.jl
+++ b/src/Translation.jl
@@ -130,9 +130,9 @@ julia> constraints_list(tr)
  HalfSpace{Float64,LazySets.Arrays.SingleEntryVector{Float64}}([1.0, 0.0, 0.0], 5.0)
  HalfSpace{Float64,LazySets.Arrays.SingleEntryVector{Float64}}([0.0, 1.0, 0.0], 3.0)
  HalfSpace{Float64,LazySets.Arrays.SingleEntryVector{Float64}}([0.0, 0.0, 1.0], 3.0)
- HalfSpace{Float64,Array{Float64,1}}([-1.0, -0.0, -0.0], -3.0)
- HalfSpace{Float64,Array{Float64,1}}([-0.0, -1.0, -0.0], -1.0)
- HalfSpace{Float64,Array{Float64,1}}([-0.0, -0.0, -1.0], -1.0)
+ HalfSpace{Float64,LazySets.Arrays.SingleEntryVector{Float64}}([-1.0, 0.0, 0.0], -3.0)
+ HalfSpace{Float64,LazySets.Arrays.SingleEntryVector{Float64}}([0.0, -1.0, 0.0], -1.0)
+ HalfSpace{Float64,LazySets.Arrays.SingleEntryVector{Float64}}([0.0, 0.0, -1.0], -1.0)
 ```
 """
 struct Translation{N<:Real, VN<:AbstractVector{N}, S<:LazySet{N}} <: LazySet{N}
diff --git a/test/unit_util.jl b/test/unit_util.jl
index 3040c9d55a..4c4a41fec2 100644
--- a/test/unit_util.jl
+++ b/test/unit_util.jl
@@ -51,6 +51,7 @@ for _dummy_ in 1:1 # avoid global variable warnings
         y1 = N[3, 0]
         x2 = SingleEntryVector(2, 3, N(2))
         y2 = SingleEntryVector(1, 2, N(3))
+        @test -x2 == SingleEntryVector(2, 3, N(-2))
         @test inner(x1, A, y1) == dot(x1, A * y1) == inner(x2, A, y2) ==
               dot(x2, A * y2) == N(12)