diff --git a/.travis.yml b/.travis.yml
index df63021f35aa..9f08e176eed2 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,7 +6,7 @@ os:
   - osx
 julia:
   - 0.4
-  #- nightly
+  - nightly
 
 # dependent apt packages
 addons:
diff --git a/REQUIRE b/REQUIRE
index fea260919fbc..d97c567e15db 100644
--- a/REQUIRE
+++ b/REQUIRE
@@ -1,4 +1,5 @@
-julia 0.4
+julia 0.4+
+Compat
 Formatting
 BinDeps
 JSON
diff --git a/src/MXNet.jl b/src/MXNet.jl
index 16ad415efe52..cdbacbe64be0 100644
--- a/src/MXNet.jl
+++ b/src/MXNet.jl
@@ -6,6 +6,10 @@ module MXNet
 # functions with the same names as built-in utilities like "zeros", etc.
 export mx
 module mx
+
+using Compat
+import Compat.String
+
 using Formatting
 
 # Functions from base that we can safely extend and that are defined by libmxnet.
diff --git a/src/base.jl b/src/base.jl
index de48241ac7e9..bd67a7c2ac52 100644
--- a/src/base.jl
+++ b/src/base.jl
@@ -42,7 +42,7 @@ function mx_get_last_error()
   if msg == C_NULL
     throw(MXError("Failed to get last error message"))
   end
-  return bytestring(msg)
+  return @compat String(msg)
 end
 
 "Utility macro to call MXNet API functions"
@@ -189,10 +189,19 @@ function _defstruct_impl(is_immutable, name, fields)
   if isa(name, Symbol)
     name       = esc(name)
     super_name = :Any
+  elseif VERSION >= v"0.5-"
+    @assert(isa(name, Expr) && name.head == :(<:) && length(name.args) == 2 &&
+            isa(name.args[1], Symbol) && isa(name.args[2], Symbol),
+            "name must be of form 'Name <: SuperType'")
+
+    super_name = esc(name.args[2])
+    name       = esc(name.args[1])
   else
-    @assert(isa(name, Expr) && name.head == :comparison && length(name.args) == 3 && name.args[2] == :(<:),
+    @assert(isa(name, Expr) && name.head == :comparison &&
+            length(name.args) == 3 && name.args[2] == :(<:) &&
+            isa(name.args[1], Symbol) && isa(name.args[3], Symbol),
             "name must be of form 'Name <: SuperType'")
-    @assert(isa(name.args[1], Symbol) && isa(name.args[3], Symbol))
+
     super_name = esc(name.args[3])
     name       = esc(name.args[1])
   end
diff --git a/src/executor.jl b/src/executor.jl
index e4b943c0c764..86f3f65921f4 100644
--- a/src/executor.jl
+++ b/src/executor.jl
@@ -221,5 +221,5 @@ Can be used to get an estimated about the memory cost.
 function debug_str(self :: Executor)
   s_ref = Ref{Cstring}()
   @mxcall(:MXExecutorPrint, (MX_handle, Ptr{Cstring}), self.handle, s_ref)
-  bytestring(s_ref[])
+  @compat String(s_ref[])
 end
diff --git a/src/initializer.jl b/src/initializer.jl
index 00e71b19c3cd..8be33bdf66d2 100644
--- a/src/initializer.jl
+++ b/src/initializer.jl
@@ -138,12 +138,6 @@ function _init_weight(self :: XavierInitializer, name :: Base.Symbol, array :: N
   fan_in  = prod(dims[2:end])
   fan_out = dims[1]
 
-  if self.distribution == xv_uniform
-    func(σ, data) = rand!(-σ, σ, data)
-  elseif self.distribution == xv_normal
-    func(σ, data) = randn!(0.0, σ, data)
-  end
-
   if self.regularization == xv_avg
     factor = (fan_in + fan_out) / 2
   elseif self.regularization == xv_in
@@ -154,5 +148,9 @@ function _init_weight(self :: XavierInitializer, name :: Base.Symbol, array :: N
 
   σ = √(self.magnitude / factor)
 
-  func(σ, array)
+  if self.distribution == xv_uniform
+    rand!(-σ, σ, array)
+  elseif self.distribution == xv_normal
+    randn!(0.0, σ, array)
+  end
 end
diff --git a/src/io.jl b/src/io.jl
index 99fcd8516c6b..46fbcfe86a2d 100644
--- a/src/io.jl
+++ b/src/io.jl
@@ -584,7 +584,7 @@ function _define_data_iter_creator(hdr :: MX_handle; gen_docs::Bool=false)
           (MX_handle, Ref{char_p}, Ref{char_p}, Ref{MX_uint}, Ref{char_pp}, Ref{char_pp}, Ref{char_pp}),
           hdr, ref_name, ref_desc, ref_narg, ref_arg_names, ref_arg_types, ref_arg_descs)
 
-  iter_name = symbol(bytestring(ref_name[]))
+  iter_name = Symbol(String(ref_name[]))
 
   if gen_docs
     if endswith(string(iter_name), "Iter")
@@ -592,7 +592,7 @@ function _define_data_iter_creator(hdr :: MX_handle; gen_docs::Bool=false)
     else
       f_desc = ""
     end
-    f_desc *= bytestring(ref_desc[]) * "\n\n"
+    f_desc *= String(ref_desc[]) * "\n\n"
     f_desc *= ":param Base.Symbol data_name: keyword argument, default ``:data``. The name of the data.\n"
     f_desc *= ":param Base.Symbol label_name: keyword argument, default ``:softmax_label``. " *
               "The name of the label. Could be ``nothing`` if no label is presented in this dataset.\n\n"
@@ -617,7 +617,7 @@ function _define_data_iter_creator(hdr :: MX_handle; gen_docs::Bool=false)
 
   # add an alias XXXProvider => XXXIter
   if endswith(string(iter_name), "Iter")
-    alias_name = symbol(string(iter_name)[1:end-4] * "Provider")
+    alias_name = Symbol(string(iter_name)[1:end-4] * "Provider")
     eval(:($alias_name = $iter_name))
   end
 end
diff --git a/src/kvstore.jl b/src/kvstore.jl
index d52433f567b2..bc2e65c6fdd3 100644
--- a/src/kvstore.jl
+++ b/src/kvstore.jl
@@ -87,7 +87,7 @@ end
 function get_type(self :: KVStore)
   type_ref = Ref{char_p}(0)
   @mxcall(:MXKVStoreGetType, (MX_handle, Ref{char_p}), self, type_ref)
-  return symbol(bytestring(type_ref[]))
+  return Symbol(@compat String(type_ref[]))
 end
 
 function get_num_workers(self :: KVStore)
diff --git a/src/metric.jl b/src/metric.jl
index 7e76b969d0a0..1f601980ad13 100644
--- a/src/metric.jl
+++ b/src/metric.jl
@@ -208,7 +208,7 @@ type MultiACE <: AbstractEvalMetric
 end
 
 function get(metric :: MultiACE)
-  aces = [(symbol("ACE_$(i-0)"), - metric.aces[i] / metric.counts[i]) for i in 1:length(metric.aces)]
+  aces = [(Symbol("ACE_$(i-0)"), - metric.aces[i] / metric.counts[i]) for i in 1:length(metric.aces)]
   push!(aces, (:ACE, - Base.sum(metric.aces) / Base.sum(metric.counts)))
   return aces
 end
diff --git a/src/model.jl b/src/model.jl
index 3984eb9d1389..d9b81d02f3d9 100644
--- a/src/model.jl
+++ b/src/model.jl
@@ -374,7 +374,7 @@ function fit(self :: FeedForward, optimizer :: AbstractOptimizer, data :: Abstra
   for (attr, value) in list_all_attr(self.arch)
     sattr = string(attr)
     if endswith(sattr, "grad") && value == "freeze"
-      push!(freeze_names, symbol(sattr[1:end-5]))
+      push!(freeze_names, Symbol(sattr[1:end-5]))
     end
   end
   # Needs to correspond to the correct id in the update loop layer idx=1:length(param_names).
@@ -582,8 +582,8 @@ end
 function save_checkpoint(sym :: SymbolicNode, arg_params :: Dict{Base.Symbol, NDArray},
                          aux_params :: Dict{Base.Symbol, NDArray}, prefix :: AbstractString, epoch :: Int)
   save("$prefix-symbol.json", sym)
-  save_dict = merge(Dict([symbol("arg:$k") => v for (k,v) in arg_params]),
-                    Dict([symbol("aux:$k") => v for (k,v) in aux_params]))
+  save_dict = merge(Dict([Symbol("arg:$k") => v for (k,v) in arg_params]),
+                    Dict([Symbol("aux:$k") => v for (k,v) in aux_params]))
   save_filename = format("{1}-{2:04d}.params", prefix, epoch)
   save(save_filename, save_dict)
   info("Saved checkpoint to '$save_filename'")
@@ -596,7 +596,7 @@ function load_checkpoint(prefix :: AbstractString, epoch :: Int)
   aux_params = Dict{Base.Symbol, NDArray}()
   for (k,v) in saved_dict
     tp, name = split(string(k), ':')
-    name = symbol(name)
+    name = Symbol(name)
     if tp == "arg"
       arg_params[name] = v
     else
diff --git a/src/name.jl b/src/name.jl
index 5ebf10917ce6..2ec531834232 100644
--- a/src/name.jl
+++ b/src/name.jl
@@ -9,14 +9,14 @@ import Base: get!
 # is automatically generated based on the hint string.
 function _default_get_name!(counter :: NameCounter, name :: NameType, hint :: NameType)
   if isa(name, Base.Symbol) || !isempty(name)
-    return symbol(name)
+    return Symbol(name)
   end
 
-  hint = symbol(hint)
+  hint = Symbol(hint)
   if !haskey(counter, hint)
     counter[hint] = 0
   end
-  name = symbol("$hint$(counter[hint])")
+  name = Symbol("$hint$(counter[hint])")
   counter[hint] += 1
   return name
 end
@@ -34,11 +34,11 @@ type PrefixNameManager <: AbstractNameManager
   prefix  :: Base.Symbol
   counter :: NameCounter
 end
-PrefixNameManager(prefix :: NameType) = PrefixNameManager(symbol(prefix), NameCounter())
+PrefixNameManager(prefix :: NameType) = PrefixNameManager(Symbol(prefix), NameCounter())
 
 function get!(manager :: PrefixNameManager, name :: NameType, hint :: NameType)
   name = _default_get_name!(manager.counter, name, hint)
-  return symbol("$(manager.prefix)$name")
+  return Symbol("$(manager.prefix)$name")
 end
 
 DEFAULT_NAME_MANAGER = BasicNameManager()
diff --git a/src/ndarray.jl b/src/ndarray.jl
index 9c4836e60771..1ed620d800e5 100644
--- a/src/ndarray.jl
+++ b/src/ndarray.jl
@@ -788,7 +788,7 @@ function load(filename::AbstractString, ::Type{NDArray})
     return [NDArray(MX_NDArrayHandle(hdr)) for hdr in pointer_to_array(out_hdrs[], out_size)]
   else
     @assert out_size == out_name_size
-    return Dict([(symbol(bytestring(k)), NDArray(MX_NDArrayHandle(hdr))) for (k,hdr) in
+    return Dict([(Symbol(@compat String(k)), NDArray(MX_NDArrayHandle(hdr))) for (k,hdr) in
                  zip(pointer_to_array(out_names[], out_size), pointer_to_array(out_hdrs[], out_size))])
   end
 end
@@ -903,11 +903,11 @@ function _import_ndarray_functions(;gen_docs=false)
             func_handle, ref_name, ref_desc, ref_narg, ref_arg_names,
             ref_arg_types, ref_arg_descs, ref_ret_type)
 
-    func_name = symbol(bytestring(ref_name[]))
+    func_name = Symbol(@compat String(ref_name[]))
 
     if gen_docs
       # generate document only
-      f_desc = bytestring(ref_desc[]) * "\n\n"
+      f_desc = @compat String(ref_desc[]) * "\n\n"
       f_desc *= _format_docstring(Int(ref_narg[]), ref_arg_names, ref_arg_types, ref_arg_descs)
       docs[func_name] = f_desc
     else
@@ -932,18 +932,18 @@ function _import_ndarray_functions(;gen_docs=false)
 
       # general ndarray function
       if arg_before_scalar
-        args = vcat([Expr(:(::), symbol("in$i"), NDArray) for i=1:n_used_vars],
-                    [Expr(:(::), symbol("sca$i"), Real) for i=1:n_scalars],
-                    [Expr(:(::), symbol("out$i"), NDArray) for i=1:n_mutate_vars])
+        args = vcat([Expr(:(::), Symbol("in$i"), NDArray) for i=1:n_used_vars],
+                    [Expr(:(::), Symbol("sca$i"), Real) for i=1:n_scalars],
+                    [Expr(:(::), Symbol("out$i"), NDArray) for i=1:n_mutate_vars])
       else
-        args = vcat([Expr(:(::), symbol("sca$i"), Real) for i=1:n_scalars],
-                    [Expr(:(::), symbol("in$i"), NDArray) for i=1:n_used_vars],
-                    [Expr(:(::), symbol("out$i"), NDArray) for i=1:n_mutate_vars])
+        args = vcat([Expr(:(::), Symbol("sca$i"), Real) for i=1:n_scalars],
+                    [Expr(:(::), Symbol("in$i"), NDArray) for i=1:n_used_vars],
+                    [Expr(:(::), Symbol("out$i"), NDArray) for i=1:n_mutate_vars])
       end
 
-      _use_vars = Expr(:ref, :MX_handle, [symbol("in$i") for i=1:n_used_vars]...)
-      _scalars  = Expr(:ref, :MX_float, [symbol("sca$i") for i=1:n_scalars]...)
-      _mut_vars = Expr(:ref, :MX_handle, [symbol("out$i") for i=1:n_mutate_vars]...)
+      _use_vars = Expr(:ref, :MX_handle, [Symbol("in$i") for i=1:n_used_vars]...)
+      _scalars  = Expr(:ref, :MX_float, [Symbol("sca$i") for i=1:n_scalars]...)
+      _mut_vars = Expr(:ref, :MX_handle, [Symbol("out$i") for i=1:n_mutate_vars]...)
 
       # XXX: hacky way of solving the problem that the arguments of `dot` should be swapped
       # See https://github.com/dmlc/MXNet.jl/issues/55
@@ -955,7 +955,7 @@ function _import_ndarray_functions(;gen_docs=false)
       if n_mutate_vars == 1
         stmt_ret = :(return out1)
       else
-        stmt_ret = Expr(:return, Expr(:tuple, [symbol("out$i") for i=1:n_mutate_vars]...))
+        stmt_ret = Expr(:return, Expr(:tuple, [Symbol("out$i") for i=1:n_mutate_vars]...))
       end
 
       func_body = Expr(:block, stmt_call, stmt_ret)
diff --git a/src/nn-factory.jl b/src/nn-factory.jl
index 984f50a5f782..3725587f37a1 100644
--- a/src/nn-factory.jl
+++ b/src/nn-factory.jl
@@ -39,10 +39,10 @@ function MLP(input, spec; hidden_activation::Base.Symbol=:relu, prefix=gensym())
       n_unit = s
       act_type = hidden_activation
     end
-    input = FullyConnected(input, name=symbol(prefix, "fc$i"), num_hidden=n_unit)
+    input = FullyConnected(input, name=Symbol(prefix, "fc$i"), num_hidden=n_unit)
     if i < n_layer || isa(s, Tuple)
       # will not add activation unless the user explicitly specified
-      input = Activation(input, name=symbol(prefix, "$act_type$i"), act_type=act_type)
+      input = Activation(input, name=Symbol(prefix, "$act_type$i"), act_type=act_type)
     end
   end
 
diff --git a/src/symbolic-node.jl b/src/symbolic-node.jl
index 4ce5b59a18ea..da251e4cc74f 100644
--- a/src/symbolic-node.jl
+++ b/src/symbolic-node.jl
@@ -62,7 +62,7 @@ macro _list_symbol_info(self, func_name)
             $self, ref_sz, ref_names)
     narg = ref_sz[]
     names = pointer_to_array(ref_names[], narg)
-    names = [symbol(bytestring(x)) for x in names]
+    names = [Symbol(@compat String(x)) for x in names]
     return names
   end
 end
@@ -129,15 +129,15 @@ end
    :return: The value belonging to key as a :class:`Nullable`.
 =#
 function get_attr(self :: SymbolicNode, key :: Symbol)
-  key_s = bytestring(string(key))
+  key_s = @compat String(string(key))
   ref_out = Ref{Cstring}()
   ref_success = Ref{Cint}(-1)
   @mxcall(:MXSymbolGetAttr, (MX_handle, Cstring, Ref{Cstring}, Ref{Cint}),
           self, key_s, ref_out, ref_success)
   if ref_success[] == 1
-    return Nullable{ByteString}(bytestring(ref_out[]))
+    return Nullable{String}(@compat String(ref_out[]))
   else
-    return Nullable{ByteString}()
+    return Nullable{String}()
   end
 end
 
@@ -154,10 +154,10 @@ function list_attr(self :: SymbolicNode)
             self, ref_sz, ref_strings)
   narg = 2*ref_sz[]
   strings = pointer_to_array(ref_strings[], narg)
-  out = Dict{Symbol, ByteString}()
+  out = Dict{Symbol, String}()
   for i in 1:2:narg
-    key = symbol(bytestring(strings[i]))
-    value = bytestring(strings[i+1])
+    key = Symbol(@compat String(strings[i]))
+    value = @compat String(strings[i+1])
     out[key] = value
   end
   return out
@@ -176,10 +176,10 @@ function list_all_attr(self :: SymbolicNode)
             self, ref_sz, ref_strings)
   narg = 2*ref_sz[]
   strings = pointer_to_array(ref_strings[], narg)
-  out = Dict{Symbol, ByteString}()
+  out = Dict{Symbol, String}()
   for i in 1:2:narg
-    key = symbol(bytestring(strings[i]))
-    value = bytestring(strings[i+1])
+    key = Symbol(@compat String(strings[i]))
+    value = @compat String(strings[i+1])
     out[key] = value
   end
   return out
@@ -198,8 +198,8 @@ end
       cause unexpected behavior and inconsistency.
 =#
 function set_attr(self :: SymbolicNode, key :: Symbol, value :: AbstractString)
-  key_s = bytestring(string(key))
-  value_s = bytestring(value)
+  key_s = @compat String(string(key))
+  value_s = @compat String(value)
 
   @mxcall(:MXSymbolSetAttr, (MX_handle, Cstring, Cstring), self, key_s, value_s)
 end
@@ -325,7 +325,7 @@ end
    indicating the index, as in the list of :func:`list_outputs`.
 =#
 function Base.getindex(self :: SymbolicNode, idx :: Union{Base.Symbol, AbstractString})
-  idx   = symbol(idx)
+  idx   = Symbol(idx)
   i_idx = find(idx .== list_outputs(self))
   @assert(length(i_idx) > 0, "Cannot find output with name '$idx'")
   @assert(length(i_idx) < 2, "Found duplicated output with name '$idx'")
@@ -474,7 +474,7 @@ end
 function to_json(self :: SymbolicNode)
   ref_json = Ref{char_p}(0)
   @mxcall(:MXSymbolSaveToJSON, (MX_handle, Ref{char_p}), self, ref_json)
-  return bytestring(ref_json[])
+  return @compat String(ref_json[])
 end
 
 #=doc
@@ -533,20 +533,20 @@ function _define_atomic_symbol_creator(hdr :: MX_handle; gen_docs=false)
           hdr, ref_name, ref_desc, ref_nargs, ref_arg_names, ref_arg_types, ref_arg_descs,
           ref_kv_nargs, ref_ret_type)
 
-  func_name_s= bytestring(ref_name[])
-  func_name  = symbol(func_name_s)
-  kv_nargs_s = bytestring(ref_kv_nargs[])
-  kv_nargs   = symbol(kv_nargs_s)
+  func_name_s= @compat String(ref_name[])
+  func_name  = Symbol(func_name_s)
+  kv_nargs_s = @compat String(ref_kv_nargs[])
+  kv_nargs   = Symbol(kv_nargs_s)
 
   if gen_docs
-    f_desc = bytestring(ref_desc[]) * "\n\n"
+    f_desc = @compat String(ref_desc[]) * "\n\n"
     if !isempty(kv_nargs_s)
       f_desc *= "This function support variable length positional :class:`SymbolicNode` inputs.\n\n"
     end
     f_desc *= _format_docstring(Int(ref_nargs[]), ref_arg_names, ref_arg_types, ref_arg_descs)
     f_desc *= ":param Symbol name: The name of the :class:`SymbolicNode`. (e.g. `:my_symbol`), optional.\n"
     f_desc *= ":param Dict{Symbol, AbstractString} attrs: The attributes associated with this :class:`SymbolicNode`.\n\n"
-    f_desc *= ":return: $(_format_typestring(bytestring(ref_ret_type[]))).\n\n"
+    f_desc *= ":return: $(_format_typestring(@compat String(ref_ret_type[]))).\n\n"
     return (func_name, f_desc)
   end
 
@@ -565,7 +565,7 @@ function _define_atomic_symbol_creator(hdr :: MX_handle; gen_docs=false)
     symbol_kws = Dict{Symbol, SymbolicNode}()
     attrs = Dict{Symbol, AbstractString}()
 
-    $(if kv_nargs != symbol("")
+    $(if kv_nargs != Symbol("")
       quote
         if !in($kv_nargs_s, param_keys)
           push!(param_keys, $kv_nargs_s)
@@ -593,7 +593,7 @@ function _define_atomic_symbol_creator(hdr :: MX_handle; gen_docs=false)
     if length(args) != 0 && length(symbol_kws) != 0
       @assert(false, $func_name_s * " only accepts Symbols either as positional or keyword arguments, not both.")
     end
-    $(if kv_nargs != symbol("")
+    $(if kv_nargs != Symbol("")
       quote
         if length(symbol_kws) > 0
           @assert(false, $func_name_s * " takes variable number of SymbolicNode arguments, " *
diff --git a/src/util.jl b/src/util.jl
index d6ce97a3e5ca..73c3316fa9f7 100644
--- a/src/util.jl
+++ b/src/util.jl
@@ -75,14 +75,14 @@ function _format_docstring(narg::Int, arg_names::Ref{char_pp}, arg_types::Ref{ch
   docstrings = AbstractString[]
 
   for i = 1:narg
-    arg_name = bytestring(arg_names[i])
+    arg_name = @compat String(arg_names[i])
     if arg_name ∈ param_keys && remove_dup
       continue
     end
     push!(param_keys, arg_name)
 
-    arg_type = _format_typestring(bytestring(arg_types[i]))
-    arg_desc = bytestring(arg_descs[i])
+    arg_type = _format_typestring(@compat String(arg_types[i]))
+    arg_desc = @compat String(arg_descs[i])
     push!(docstrings, ":param $arg_name: $arg_desc\n:type $arg_name: $arg_type\n\n")
   end
   return join(docstrings, "\n")
diff --git a/src/visualize.jl b/src/visualize.jl
index b1fa90ff3851..3d46b9c38cb3 100644
--- a/src/visualize.jl
+++ b/src/visualize.jl
@@ -117,10 +117,10 @@ function to_graphviz(network :: SymbolicNode; title="Network Visualization", inp
         attr = Dict(:dir => :back, :arrowtail => :open, :color => "#737373")
         if draw_shape
           if input_node["op"] != "null"
-            key   = symbol(input_name, "_output")
+            key   = Symbol(input_name, "_output")
             shape = shape_dict[key][1:end-1]
           else
-            key   = symbol(input_name)
+            key   = Symbol(input_name)
             shape = shape_dict[key][1:end-1]
           end
           label = "(" * join([string(x) for x in shape], ",") * ")"
diff --git a/test/unittest/name.jl b/test/unittest/name.jl
index a7dd6f7bfc35..aca039670286 100644
--- a/test/unittest/name.jl
+++ b/test/unittest/name.jl
@@ -10,8 +10,8 @@ function test_default()
   @test get!(mx.DEFAULT_NAME_MANAGER, string(name), "") == name
 
   hint = name
-  @test get!(mx.DEFAULT_NAME_MANAGER, "", hint) == symbol("$(hint)0")
-  @test get!(mx.DEFAULT_NAME_MANAGER, "", string(hint)) == symbol("$(hint)1")
+  @test get!(mx.DEFAULT_NAME_MANAGER, "", hint) == Symbol("$(hint)0")
+  @test get!(mx.DEFAULT_NAME_MANAGER, "", string(hint)) == Symbol("$(hint)1")
 end
 
 function test_prefix()
@@ -21,8 +21,8 @@ function test_prefix()
   prefix = :_____foobar_____
 
   prefix_manager = mx.PrefixNameManager(prefix)
-  @test get!(prefix_manager, name, "") == symbol("$prefix$name")
-  @test get!(prefix_manager, "", name) == symbol("$prefix$(name)0")
+  @test get!(prefix_manager, name, "") == Symbol("$prefix$name")
+  @test get!(prefix_manager, "", name) == Symbol("$prefix$(name)0")
 end
 
 test_default()
diff --git a/test/unittest/ndarray.jl b/test/unittest/ndarray.jl
index 67bff2959c8a..444aa90616fe 100644
--- a/test/unittest/ndarray.jl
+++ b/test/unittest/ndarray.jl
@@ -202,7 +202,7 @@ function test_saveload()
   end
 
   # save and load dictionary of ndarrays
-  names = [symbol("array$i") for i = 1:n_arrays]
+  names = [Symbol("array$i") for i = 1:n_arrays]
   dict = Dict([n => v for (n,v) in zip(names, nd_arrays)])
   mx.save(fname, dict)
   data = mx.load(fname, mx.NDArray)