diff --git a/Project.toml b/Project.toml
index 3a0aca0c5..fccf9e0d0 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "DataDrivenDiffEq"
 uuid = "2445eb08-9709-466a-b3fc-47e12bd697a2"
 authors = ["Julius Martensen <julius.martensen@gmail.com>"]
-version = "0.5.6"
+version = "0.5.7"
 
 [deps]
 Compat = "34da2185-b29b-5c13-b0c7-acf172513d20"
diff --git a/src/basis.jl b/src/basis.jl
index a2afce196..e2c21ff85 100644
--- a/src/basis.jl
+++ b/src/basis.jl
@@ -146,7 +146,7 @@ function update!(b::Basis, eval_expression = false)
     return
 end
 
-function unique(b::AbstractArray{Num}, simplify_eqs = false)
+function unique(b::AbstractArray{Num}, simplify_eqs::Bool)
     b = simplify_eqs ? simplify.(b) : b
     returns = ones(Bool, size(b)...)
     N = maximum(eachindex(b))
@@ -156,7 +156,7 @@ function unique(b::AbstractArray{Num}, simplify_eqs = false)
     return b[returns]
 end
 
-function Base.unique!(b::AbstractArray, simplify_eqs = false)
+function Base.unique!(b::AbstractArray, simplify_eqs::Bool)
     bs = simplify_eqs ? simplify.(b) : b
     removes = zeros(Bool, size(bs)...)
     N = maximum(eachindex(bs))
@@ -166,7 +166,7 @@ function Base.unique!(b::AbstractArray, simplify_eqs = false)
     deleteat!(b, removes)
 end
 
-function unique(b::AbstractArray{Equation}, simplify_eqs = false)
+function unique(b::AbstractArray{Equation}, simplify_eqs::Bool)
     b = simplify_eqs ? simplify.(b) : b
     returns = ones(Bool, size(b)...)
     N = maximum(eachindex(b))
@@ -176,7 +176,7 @@ function unique(b::AbstractArray{Equation}, simplify_eqs = false)
     return b[returns]
 end
 
-function Base.unique!(b::AbstractArray{Equation}, simplify_eqs = false)
+function Base.unique!(b::AbstractArray{Equation}, simplify_eqs::Bool)
     bs = [bi.rhs for bi in b]
     bs = simplify_eqs ? simplify.(bs) : bs
     removes = zeros(Bool, size(bs)...)