diff --git a/REQUIRE b/REQUIRE
index 9b6c163..b921bdd 100644
--- a/REQUIRE
+++ b/REQUIRE
@@ -6,4 +6,5 @@ SymEngine
 DataStructures
 Reexport
 FillArrays
-LazySets
+LazySets 1.5.3
+Compat
diff --git a/src/SX.jl b/src/SX.jl
index 2c9fb3c..68ba019 100644
--- a/src/SX.jl
+++ b/src/SX.jl
@@ -2,6 +2,11 @@ __precompile__(true)
 
 module SX
 
+#=========================================
+Compatibility for previous Julia versions
+=========================================#
+include("compat.jl")
+
 import DataStructures, FillArrays
 using EzXML, Reexport
 @reexport using HybridSystems, MathematicalSystems, SymEngine
diff --git a/src/compat.jl b/src/compat.jl
new file mode 100644
index 0000000..55b43d1
--- /dev/null
+++ b/src/compat.jl
@@ -0,0 +1,10 @@
+using Compat
+using Compat: @warn
+
+@static if VERSION >= v"0.7"
+    const _parse_s = Base.Meta.parse
+    const _parse_t = Base.parse
+else
+    const _parse_s = parse
+    const _parse_t = parse
+end
diff --git a/src/convert.jl b/src/convert.jl
index 65084aa..1da8f0e 100644
--- a/src/convert.jl
+++ b/src/convert.jl
@@ -143,7 +143,7 @@ function is_hyperplane(expr::Expr)::Bool
     # convert to symengine expressions
     lhs = convert(Basic, expr.args[1])
 
-    if :args in fieldnames(expr.args[2])
+    if :args in fieldnames(typeof(expr.args[2]))
         # treats the 4 in :(2*x1 = 4)
         rhs = convert(Basic, expr.args[2].args[2])
     else
@@ -276,7 +276,7 @@ function convert(::Type{LazySets.Hyperplane{N}}, expr::Expr; vars::Vector{SymEng
     lhs = convert(Basic, expr.args[1])
 
     # treats the 4 in :(2*x1 = 4)
-    rhs = :args in fieldnames(expr.args[2]) ? convert(Basic, expr.args[2].args[2]) : convert(Basic, expr.args[2])
+    rhs = :args in fieldnames(typeof(expr.args[2])) ? convert(Basic, expr.args[2].args[2]) : convert(Basic, expr.args[2])
 
     # a1 x1 + ... + an xn + K = 0
     eq = lhs - rhs
@@ -336,7 +336,7 @@ function free_symbols(expr::Expr, set_type::Type{<:LazySets.Hyperplane})
     lhs = convert(Basic, expr.args[1])
 
     # treats the 4 in :(2*x1 = 4)
-    rhs = :args in fieldnames(expr.args[2]) ? convert(Basic, expr.args[2].args[2]) : convert(Basic, expr.args[2])
+    rhs = :args in fieldnames(typeof(expr.args[2])) ? convert(Basic, expr.args[2].args[2]) : convert(Basic, expr.args[2])
     return free_symbols(lhs - rhs)
 end
 
diff --git a/src/io.jl b/src/io.jl
index 1ae518e..a19f58a 100644
--- a/src/io.jl
+++ b/src/io.jl
@@ -102,19 +102,19 @@ function readsxmodel(file; raw_dict=false,
     transitionlabels = Set{String}()
 
     # vector with the invariants for each location
-    invariants = Vector{Vector{Expr}}(nlocations)
+    invariants = Vector{Vector{Expr}}(undef, nlocations)
 
     # vector with the ODE flow for each location
-    flows = Vector{Vector{Expr}}(nlocations)
+    flows = Vector{Vector{Expr}}(undef, nlocations)
 
     # assignments for each transition
-    assignments = Vector{Vector{Expr}}(ntransitions)
+    assignments = Vector{Vector{Expr}}(undef, ntransitions)
 
     # guards for each transition; subsets of state space where the state needs
     # to be to make the transition
-    guards = Vector{Vector{Expr}}(ntransitions)
+    guards = Vector{Vector{Expr}}(undef, ntransitions)
 
-    switchings = Vector{AbstractSwitching}(ntransitions)
+    switchings = Vector{AbstractSwitching}(undef, ntransitions)
 
     HDict = Dict("automaton"=>automaton,
                  "variables"=>variables,
diff --git a/src/parse.jl b/src/parse.jl
index d8a431a..5abac40 100644
--- a/src/parse.jl
+++ b/src/parse.jl
@@ -135,11 +135,11 @@ function parse_sxmath(s; assignment=false)
     count_right_parentheses = s -> count(c -> c == ')', collect(s))
     @assert count_left_parentheses(s) == count_right_parentheses(s) "the expression $(s) is not well formed"
 
-    expr = strip.(split(replace(s, "&&", "&"), "&"))
+    expr = strip.(split(replace(s, "&&" => "&"), "&"))
     if assignment
-        expr = replace.(expr, ":=", "=")
+        expr = replace.(expr, Ref(":=" => "="))
     end
-    expr = replace.(expr, "==", "=")
+    expr = replace.(expr, Ref("==" => "="))
 
     # remove irrelevant parentheses from the beginning and the end
     for (i, expri) in enumerate(expr)
@@ -156,7 +156,7 @@ function parse_sxmath(s; assignment=false)
         end
     end
 
-    return parse.(expr)
+    return _parse_s.(expr)
 end
 
 """
@@ -248,9 +248,9 @@ function add_variable!(variables, field, id=1)
     # d1 and d2 are the dimensions (d1=d2=1 for scalars)
     @assert field["d1"] == "1" && field["d2"] == "1"
 
-    varname = parse(field["name"])
-    islocal = haskey(field, "local") ? parse(field["local"]) : false
-    iscontrolled = haskey(field, "controlled") ? parse(field["controlled"]) : true
+    varname = _parse_s(field["name"])
+    islocal = haskey(field, "local") ? _parse_s(field["local"]) : false
+    iscontrolled = haskey(field, "controlled") ? _parse_s(field["controlled"]) : true
     dynamicstype = haskey(field, "dynamics") ? field["dynamics"] : "any"
 
     variables[varname] = Dict("local"=>islocal,
@@ -293,7 +293,7 @@ and similarly `f` is the list of ODEs that define the flow for this location.
 Both objects are vectors of symbolic expressions `Expr`.
 """
 function parse_location(field)
-    id = parse(Int, field["id"])
+    id = _parse_t(Int, field["id"])
     local I, f
     for element in eachelement(field)
         if nodename(element) == "invariant"
@@ -301,7 +301,7 @@ function parse_location(field)
         elseif nodename(element) == "flow"
             f = parse_sxmath(nodecontent(element))
         else
-            warn("field $(nodename(element)) in location $(field["id"]) is ignored")
+            @warn("field $(nodename(element)) in location $(field["id"]) is ignored")
         end
     end
     return (id, I, f)
@@ -330,7 +330,7 @@ the "assignment", or both); in that case this function returns an empty of
 expressions for those cases.
 """
 function parse_transition(field)
-    q, r = parse(Int, field["source"]), parse(Int, field["target"])
+    q, r = _parse_t(Int, field["source"]), _parse_t(Int, field["target"])
     G = Vector{Expr}()
     A = Vector{Expr}()
     for element in eachelement(field)
@@ -339,7 +339,7 @@ function parse_transition(field)
         elseif nodename(element) == "assignment"
             A = parse_sxmath(nodecontent(element), assignment=true)
         else
-            warn("field $(nodename(element)) in transition $(field["source"]) → $(field["target"]) is ignored")
+            @warn("field $(nodename(element)) in transition $(field["source"]) → $(field["target"]) is ignored")
         end
     end
     return (q, r, G, A)
diff --git a/src/symbolic.jl b/src/symbolic.jl
index d83c9ca..e93ef96 100644
--- a/src/symbolic.jl
+++ b/src/symbolic.jl
@@ -60,7 +60,7 @@ function linearHS(HDict; ST=ConstrainedLinearControlContinuousSystem,
     nlocations, ntransitions = HDict["nlocations"], HDict["ntransitions"]
 
     # vector of modes (flows, invariants)
-    modes = Vector{ST}(nlocations)
+    modes = Vector{ST}(undef, nlocations)
 
     for id_location in eachindex(flows)
 
@@ -79,10 +79,10 @@ function linearHS(HDict; ST=ConstrainedLinearControlContinuousSystem,
         local_state_variables = convert.(Basic, [fi.args[1].args[1] for fi in flows[id_location]])
 
         # dynamics matrix
-        A = Matrix{N}(n, n)
+        A = Matrix{N}(undef, n, n)
 
         # forcing terms
-        B = Matrix{N}(n, m)
+        B = Matrix{N}(undef, n, m)
         C = zeros(N, n) # constant terms
 
         # track if there are constant terms
@@ -153,7 +153,7 @@ function linearHS(HDict; ST=ConstrainedLinearControlContinuousSystem,
     end
 
     # reset maps (assignments, guards) for each transition (equations)
-    resetmaps = Vector{STD}(ntransitions)
+    resetmaps = Vector{STD}(undef, ntransitions)
 
     for id_transition in eachindex(assignments)
 
@@ -172,10 +172,10 @@ function linearHS(HDict; ST=ConstrainedLinearControlContinuousSystem,
         local_state_variables = convert.(Basic, [ai.args[1].args[1] for ai in assignments[id_transition]])
 
         # dynamics matrix
-        Ar = Matrix{N}(n, n)
+        Ar = Matrix{N}(undef, n, n)
 
         # forcing terms
-        Br = Matrix{N}(n, m)
+        Br = Matrix{N}(undef, n, m)
         Cr = zeros(N, n) # constant terms
 
         # track if there are constant terms
diff --git a/test/REQUIRE b/test/REQUIRE
new file mode 100644
index 0000000..137767a
--- /dev/null
+++ b/test/REQUIRE
@@ -0,0 +1 @@
+julia 0.6
diff --git a/test/runtests.jl b/test/runtests.jl
index 23ec016..8d92a7c 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -1,5 +1,5 @@
 using SX
-using Base.Test
+using Compat, Compat.Test
 
 include("unit_examples.jl")
 include("unit_parse.jl")