diff --git a/REQUIRE b/REQUIRE
index 8584c242ff..c3231e7a61 100644
--- a/REQUIRE
+++ b/REQUIRE
@@ -7,4 +7,4 @@ Reexport
 WeakRefStrings 0.4.0
 DataStreams 0.3.0
 CodecZlib 0.4
-Compat 0.36.0
+Compat 0.40.0
diff --git a/src/DataFrames.jl b/src/DataFrames.jl
index f747b52f8e..97439fbc79 100644
--- a/src/DataFrames.jl
+++ b/src/DataFrames.jl
@@ -10,6 +10,14 @@ module DataFrames
 using Reexport, StatsBase, SortingAlgorithms, Compat
 @reexport using CategoricalArrays, Missings
 using Base: Sort, Order
+using Compat: pairs
+
+if VERSION >= v"0.7.0-DEV.2915"
+    using Unicode
+end
+if VERSION >= v"0.7.0-DEV.3052"
+    using Printf
+end
 
 ##############################################################################
 ##
diff --git a/src/abstractdataframe/io.jl b/src/abstractdataframe/io.jl
index 8c68c3cb98..c6c3e1d262 100644
--- a/src/abstractdataframe/io.jl
+++ b/src/abstractdataframe/io.jl
@@ -229,7 +229,7 @@ Data.streamfrom(source::DataFrame, ::Type{Data.Field}, ::Type{T}, row, col) wher
 Data.streamtypes(::Type{DataFrame}) = [Data.Column, Data.Field]
 Data.weakrefstrings(::Type{DataFrame}) = true
 
-allocate(::Type{T}, rows, ref) where {T} = Vector{T}(rows)
+allocate(::Type{T}, rows, ref) where {T} = Vector{T}(uninitialized, rows)
 allocate(::Type{CategoricalString{R}}, rows, ref) where {R} = CategoricalArray{String, 1, R}(rows)
 allocate(::Type{Union{CategoricalString{R}, Missing}}, rows, ref) where {R} = CategoricalArray{Union{String, Missing}, 1, R}(rows)
 allocate(::Type{CategoricalValue{T, R}}, rows, ref) where {T, R} =
diff --git a/src/abstractdataframe/sort.jl b/src/abstractdataframe/sort.jl
index 5d5653dda8..db7bf98234 100644
--- a/src/abstractdataframe/sort.jl
+++ b/src/abstractdataframe/sort.jl
@@ -30,7 +30,7 @@ _getcol(x) = x
 # Get an Ordering for a single column
 ###
 function ordering(col_ord::UserColOrdering, lt::Function, by::Function, rev::Bool, order::Ordering)
-    for (k,v) in col_ord.kwargs
+    for (k,v) in pairs(col_ord.kwargs)
         if     k == :lt;    lt    = v
         elseif k == :by;    by    = v
         elseif k == :rev;   rev   = v
diff --git a/src/dataframe/dataframe.jl b/src/dataframe/dataframe.jl
index 13ca6b321c..cd72bd2093 100644
--- a/src/dataframe/dataframe.jl
+++ b/src/dataframe/dataframe.jl
@@ -116,7 +116,7 @@ function DataFrame(; kwargs...)
     if isempty(kwargs)
         DataFrame(Any[], Index())
     else
-        DataFrame((k => v for (k,v) in kwargs)...)
+        DataFrame((k => v for (k,v) in pairs(kwargs))...)
     end
 end
 
diff --git a/test/cat.jl b/test/cat.jl
index 76774507c0..3ba7de2455 100644
--- a/test/cat.jl
+++ b/test/cat.jl
@@ -1,5 +1,5 @@
 module TestCat
-    using Base.Test, DataFrames
+    using Compat, Compat.Test, DataFrames
     const ≅ = isequal
 
     #
diff --git a/test/constructors.jl b/test/constructors.jl
index 916e69e9d2..fee4d03d11 100644
--- a/test/constructors.jl
+++ b/test/constructors.jl
@@ -1,5 +1,5 @@
 module TestConstructors
-    using Base.Test, DataFrames, DataFrames.Index
+    using Compat, Compat.Test, DataFrames, DataFrames.Index
     const ≅ = isequal
 
     #
diff --git a/test/conversions.jl b/test/conversions.jl
index 502660ca7c..03d74d7ef5 100644
--- a/test/conversions.jl
+++ b/test/conversions.jl
@@ -1,5 +1,5 @@
 module TestConversions
-    using Base.Test, DataFrames
+    using Compat, Compat.Test, DataFrames
     using DataStructures: OrderedDict, SortedDict
     const ≅ = isequal
 
diff --git a/test/data.jl b/test/data.jl
index 0e27568d68..3b5bc949a9 100644
--- a/test/data.jl
+++ b/test/data.jl
@@ -1,5 +1,5 @@
 module TestData
-    using Base.Test, DataFrames
+    using Compat, Compat.Test, DataFrames
     importall Base # so that we get warnings for conflicts
     const ≅ = isequal
 
diff --git a/test/dataframe.jl b/test/dataframe.jl
index 16ceff2e4d..331318237c 100644
--- a/test/dataframe.jl
+++ b/test/dataframe.jl
@@ -1,5 +1,5 @@
 module TestDataFrame
-    using Base.Test, DataFrames
+    using Compat, Compat.Test, DataFrames
     const ≅ = isequal
     const ≇ = !isequal
 
diff --git a/test/dataframerow.jl b/test/dataframerow.jl
index c08f17254f..c0078d79f1 100644
--- a/test/dataframerow.jl
+++ b/test/dataframerow.jl
@@ -1,5 +1,5 @@
 module TestDataFrameRow
-    using Base.Test, DataFrames
+    using Compat, Compat.Test, DataFrames
 
     df = DataFrame(a=Union{Int, Missing}[1, 2, 3, 1, 2, 2],
                    b=[2.0, missing, 1.2, 2.0, missing, missing],
diff --git a/test/duplicates.jl b/test/duplicates.jl
index 4f9aeed341..da0d69a81c 100644
--- a/test/duplicates.jl
+++ b/test/duplicates.jl
@@ -1,5 +1,5 @@
 module TestDuplicates
-    using Base.Test, DataFrames
+    using Compat, Compat.Test, DataFrames
     const ≅ = isequal
 
     df = DataFrame(a = [1, 2, 3, 3, 4])
diff --git a/test/grouping.jl b/test/grouping.jl
index e04042c7f3..de1ca8bad8 100644
--- a/test/grouping.jl
+++ b/test/grouping.jl
@@ -1,5 +1,5 @@
 module TestGrouping
-    using Base.Test, DataFrames
+    using Compat, Compat.Test, DataFrames
     const ≅ = isequal
 
     srand(1)
diff --git a/test/index.jl b/test/index.jl
index 8da2e34861..9b8f33df5b 100644
--- a/test/index.jl
+++ b/test/index.jl
@@ -1,5 +1,5 @@
 module TestIndex
-using Base.Test, DataFrames, DataFrames.Index
+using Compat, Compat.Test, DataFrames, DataFrames.Index
 
 i = Index()
 push!(i, :A)
diff --git a/test/io.jl b/test/io.jl
index d4d7174a93..b77eeb7bd3 100644
--- a/test/io.jl
+++ b/test/io.jl
@@ -1,5 +1,5 @@
 module TestIO
-    using Base.Test, DataFrames, CategoricalArrays
+    using Compat, Compat.Test, DataFrames, CategoricalArrays
     using LaTeXStrings
 
     # Test LaTeX export
diff --git a/test/iteration.jl b/test/iteration.jl
index 7ddfed8000..51590160dc 100644
--- a/test/iteration.jl
+++ b/test/iteration.jl
@@ -1,5 +1,5 @@
 module TestIteration
-    using Base.Test, DataFrames
+    using Compat, Compat.Test, DataFrames
 
     dv = [1, 2, missing]
     dm = Union{Int, Missing}[1 2; 3 4]
diff --git a/test/join.jl b/test/join.jl
index 59412d762d..fb4b11e1dc 100644
--- a/test/join.jl
+++ b/test/join.jl
@@ -1,5 +1,5 @@
 module TestJoin
-    using Base.Test, DataFrames
+    using Compat, Compat.Test, DataFrames
     const ≅ = isequal
 
     name = DataFrame(ID = Union{Int, Missing}[1, 2, 3],
diff --git a/test/runtests.jl b/test/runtests.jl
index 6ab648c1e1..c54d0b9431 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -6,7 +6,7 @@ fatalerrors = length(ARGS) > 0 && ARGS[1] == "-f"
 quiet = length(ARGS) > 0 && ARGS[1] == "-q"
 anyerrors = false
 
-using Base.Test
+using Compat, Compat.Test
 using DataFrames
 
 my_tests = ["utils.jl",
diff --git a/test/show.jl b/test/show.jl
index 9b8c0b4dad..6102588637 100644
--- a/test/show.jl
+++ b/test/show.jl
@@ -1,5 +1,5 @@
 module TestShow
-    using Base.Test, DataFrames
+    using Compat, Compat.Test, DataFrames
 
     # In the future newline character \n should be added to this test case
     df = DataFrame(A = Int64[1:4;], B = ["x\"", "∀ε>0: x+ε>x", "z\$", "ABC"],
diff --git a/test/sort.jl b/test/sort.jl
index 3250410a62..30ae45eb85 100644
--- a/test/sort.jl
+++ b/test/sort.jl
@@ -1,5 +1,5 @@
 module TestSort
-    using Base.Test, DataFrames
+    using Compat, Compat.Test, DataFrames
 
     dv1 = [9, 1, 8, missing, 3, 3, 7, missing]
     dv2 = [9, 1, 8, missing, 3, 3, 7, missing]
diff --git a/test/subdataframe.jl b/test/subdataframe.jl
index 2cd00fa213..9ee4e71a48 100644
--- a/test/subdataframe.jl
+++ b/test/subdataframe.jl
@@ -1,5 +1,5 @@
 module TestSubDataFrame
-    using Base.Test, DataFrames
+    using Compat, Compat.Test, DataFrames
 
     @testset "view -- DataFrame" begin
         df = DataFrame(x = 1:10, y = 1.0:10.0)
diff --git a/test/utils.jl b/test/utils.jl
index 07b843edf5..d9e700ee32 100644
--- a/test/utils.jl
+++ b/test/utils.jl
@@ -1,5 +1,5 @@
 module TestUtils
-    using Base.Test, DataFrames, StatsBase
+    using Compat, Compat.Test, DataFrames, StatsBase
     import DataFrames: identifier
 
     @test identifier("%_B*_\tC*") == :_B_C_