diff --git a/REQUIRE b/REQUIRE
index 8aee958..0d9397e 100644
--- a/REQUIRE
+++ b/REQUIRE
@@ -1,2 +1,3 @@
 julia 0.6
 Compat 0.37.0
+Nullables 0.0.1
diff --git a/src/Parser.jl b/src/Parser.jl
index fc7b3ec..b75c09c 100644
--- a/src/Parser.jl
+++ b/src/Parser.jl
@@ -2,6 +2,7 @@ module Parser  # JSON
 
 using Compat
 using Compat.Mmap
+using Nullables
 using ..Common
 
 """
diff --git a/src/Writer.jl b/src/Writer.jl
index 7bf4905..9c00c90 100644
--- a/src/Writer.jl
+++ b/src/Writer.jl
@@ -1,6 +1,7 @@
 module Writer
 
 using Compat.Dates
+using Nullables
 using ..Common
 using ..Serializations: Serialization, StandardSerialization,
                         CommonSerialization
diff --git a/test/standard-serializer.jl b/test/standard-serializer.jl
index a5b846a..3f1bd2b 100644
--- a/test/standard-serializer.jl
+++ b/test/standard-serializer.jl
@@ -1,3 +1,5 @@
+using Nullables
+
 @testset "Symbol" begin
     symtest = Dict(:symbolarray => [:apple, :pear], :symbolsingleton => :hello)
     @test (JSON.json(symtest) == "{\"symbolarray\":[\"apple\",\"pear\"],\"symbolsingleton\":\"hello\"}"