diff --git a/src/json3.jl b/src/json3.jl
index 9cb0a65..3e03c8e 100644
--- a/src/json3.jl
+++ b/src/json3.jl
@@ -8,3 +8,6 @@ const StructTypes = JSON3.StructTypes
 
 StructTypes.StructType(::Type{<:PlotlyBase.Plot}) = JSON3.RawType()
 JSON3.rawbytes(plot::PlotlyBase.Plot) = codeunits(JSON.json(plot))
+
+StructTypes.StructType(::Type{<:HasFields}) = JSON3.RawType()
+JSON3.rawbytes(x::HasFields) = codeunits(JSON.json(x))
\ No newline at end of file
diff --git a/test/Project.toml b/test/Project.toml
index 2cfb8c8..0364274 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -2,4 +2,5 @@
 DataFrames = "a93c6f00-e57d-5684-b7b6-d8193f3e46c0"
 Dates = "ade2ca70-3891-5945-98fb-dc099432e06a"
 DelimitedFiles = "8bb1440f-4735-579b-a4ab-409b98df4dab"
+JSON3 = "0f8b85d8-7281-11e9-16c2-39a750bddbf1"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
diff --git a/test/json.jl b/test/json.jl
new file mode 100644
index 0000000..427c56e
--- /dev/null
+++ b/test/json.jl
@@ -0,0 +1,13 @@
+
+gt = PlotlyBase.GenericTrace("scatter"; x=1:10, y=(1:10).^2)
+pplot = PlotlyBase.Plot(gt)
+layout = PlotlyBase.Layout()
+
+using PlotlyBase.JSON, JSON3
+
+@testset "Convert to json" begin
+    @test JSON.json(gt) == "{\"y\":[1,4,9,16,25,36,49,64,81,100],\"type\":\"scatter\",\"x\":[1,2,3,4,5,6,7,8,9,10]}"
+    @test JSON.json(gt) == JSON3.write(gt)
+    @test JSON.json(pplot) == JSON3.write(pplot)    
+    @test JSON.json(layout) == JSON3.write(layout)
+end