diff --git a/src/args.jl b/src/args.jl
index 6f719bae..68c72455 100644
--- a/src/args.jl
+++ b/src/args.jl
@@ -685,15 +685,15 @@ function processLineArg(plotattributes::KW, arg)
         plotattributes[:linestyle] = arg
 
     elseif typeof(arg) <: Stroke
-        arg.width == nothing || (plotattributes[:linewidth] = arg.width)
-        arg.color == nothing || (plotattributes[:linecolor] = arg.color == :auto ? :auto : plot_color(arg.color))
-        arg.alpha == nothing || (plotattributes[:linealpha] = arg.alpha)
-        arg.style == nothing || (plotattributes[:linestyle] = arg.style)
+        arg.width === nothing || (plotattributes[:linewidth] = arg.width)
+        arg.color === nothing || (plotattributes[:linecolor] = arg.color == :auto ? :auto : plot_color(arg.color))
+        arg.alpha === nothing || (plotattributes[:linealpha] = arg.alpha)
+        arg.style === nothing || (plotattributes[:linestyle] = arg.style)
 
     elseif typeof(arg) <: Brush
-        arg.size  == nothing || (plotattributes[:fillrange] = arg.size)
-        arg.color == nothing || (plotattributes[:fillcolor] = arg.color == :auto ? :auto : plot_color(arg.color))
-        arg.alpha == nothing || (plotattributes[:fillalpha] = arg.alpha)
+        arg.size  === nothing || (plotattributes[:fillrange] = arg.size)
+        arg.color === nothing || (plotattributes[:fillcolor] = arg.color == :auto ? :auto : plot_color(arg.color))
+        arg.alpha === nothing || (plotattributes[:fillalpha] = arg.alpha)
 
     elseif typeof(arg) <: Arrow || arg in (:arrow, :arrows)
         plotattributes[:arrow] = arg
@@ -724,15 +724,15 @@ function processMarkerArg(plotattributes::KW, arg)
         plotattributes[:markerstrokestyle] = arg
 
     elseif typeof(arg) <: Stroke
-        arg.width == nothing || (plotattributes[:markerstrokewidth] = arg.width)
-        arg.color == nothing || (plotattributes[:markerstrokecolor] = arg.color == :auto ? :auto : plot_color(arg.color))
-        arg.alpha == nothing || (plotattributes[:markerstrokealpha] = arg.alpha)
-        arg.style == nothing || (plotattributes[:markerstrokestyle] = arg.style)
+        arg.width === nothing || (plotattributes[:markerstrokewidth] = arg.width)
+        arg.color === nothing || (plotattributes[:markerstrokecolor] = arg.color == :auto ? :auto : plot_color(arg.color))
+        arg.alpha === nothing || (plotattributes[:markerstrokealpha] = arg.alpha)
+        arg.style === nothing || (plotattributes[:markerstrokestyle] = arg.style)
 
     elseif typeof(arg) <: Brush
-        arg.size  == nothing || (plotattributes[:markersize]  = arg.size)
-        arg.color == nothing || (plotattributes[:markercolor] = arg.color == :auto ? :auto : plot_color(arg.color))
-        arg.alpha == nothing || (plotattributes[:markeralpha] = arg.alpha)
+        arg.size  === nothing || (plotattributes[:markersize]  = arg.size)
+        arg.color === nothing || (plotattributes[:markercolor] = arg.color == :auto ? :auto : plot_color(arg.color))
+        arg.alpha === nothing || (plotattributes[:markeralpha] = arg.alpha)
 
     # linealpha
     elseif allAlphas(arg)
@@ -757,9 +757,9 @@ end
 function processFillArg(plotattributes::KW, arg)
     # fr = get(plotattributes, :fillrange, 0)
     if typeof(arg) <: Brush
-        arg.size  == nothing || (plotattributes[:fillrange] = arg.size)
-        arg.color == nothing || (plotattributes[:fillcolor] = arg.color == :auto ? :auto : plot_color(arg.color))
-        arg.alpha == nothing || (plotattributes[:fillalpha] = arg.alpha)
+        arg.size  === nothing || (plotattributes[:fillrange] = arg.size)
+        arg.color === nothing || (plotattributes[:fillcolor] = arg.color == :auto ? :auto : plot_color(arg.color))
+        arg.alpha === nothing || (plotattributes[:fillalpha] = arg.alpha)
 
     elseif typeof(arg) <: Bool
         plotattributes[:fillrange] = arg ? 0 : nothing
@@ -793,10 +793,10 @@ function processGridArg!(plotattributes::KW, arg, letter)
         plotattributes[Symbol(letter, :gridstyle)] = arg
 
     elseif typeof(arg) <: Stroke
-        arg.width == nothing || (plotattributes[Symbol(letter, :gridlinewidth)] = arg.width)
-        arg.color == nothing || (plotattributes[Symbol(letter, :foreground_color_grid)] = arg.color in (:auto, :match) ? :match : plot_color(arg.color))
-        arg.alpha == nothing || (plotattributes[Symbol(letter, :gridalpha)] = arg.alpha)
-        arg.style == nothing || (plotattributes[Symbol(letter, :gridstyle)] = arg.style)
+        arg.width === nothing || (plotattributes[Symbol(letter, :gridlinewidth)] = arg.width)
+        arg.color === nothing || (plotattributes[Symbol(letter, :foreground_color_grid)] = arg.color in (:auto, :match) ? :match : plot_color(arg.color))
+        arg.alpha === nothing || (plotattributes[Symbol(letter, :gridalpha)] = arg.alpha)
+        arg.style === nothing || (plotattributes[Symbol(letter, :gridstyle)] = arg.style)
 
     # linealpha
     elseif allAlphas(arg)
@@ -822,10 +822,10 @@ function processMinorGridArg!(plotattributes::KW, arg, letter)
         plotattributes[Symbol(letter, :minorgrid)] = true
 
     elseif typeof(arg) <: Stroke
-        arg.width == nothing || (plotattributes[Symbol(letter, :minorgridlinewidth)] = arg.width)
-        arg.color == nothing || (plotattributes[Symbol(letter, :foreground_color_minor_grid)] = arg.color in (:auto, :match) ? :match : plot_color(arg.color))
-        arg.alpha == nothing || (plotattributes[Symbol(letter, :minorgridalpha)] = arg.alpha)
-        arg.style == nothing || (plotattributes[Symbol(letter, :minorgridstyle)] = arg.style)
+        arg.width === nothing || (plotattributes[Symbol(letter, :minorgridlinewidth)] = arg.width)
+        arg.color === nothing || (plotattributes[Symbol(letter, :foreground_color_minor_grid)] = arg.color in (:auto, :match) ? :match : plot_color(arg.color))
+        arg.alpha === nothing || (plotattributes[Symbol(letter, :minorgridalpha)] = arg.alpha)
+        arg.style === nothing || (plotattributes[Symbol(letter, :minorgridstyle)] = arg.style)
         plotattributes[Symbol(letter, :minorgrid)] = true
 
     # linealpha
@@ -1237,7 +1237,7 @@ end
 #     v = plotattributes[k]
 #     plotattributes[k] = if v == :match
 #         match_color
-#     elseif v == nothing
+#     elseif v === nothing
 #         plot_color(RGBA(0,0,0,0))
 #     else
 #         v
@@ -1246,7 +1246,7 @@ end
 
 function color_or_nothing!(plotattributes::KW, k::Symbol)
     v = plotattributes[k]
-    plotattributes[k] = if v == nothing || v == false
+    plotattributes[k] = if v === nothing || v == false
         RGBA{Float64}(0,0,0,0)
     elseif v != :match
         plot_color(v)
@@ -1563,11 +1563,11 @@ function _update_series_attributes!(plotattributes::KW, plt::Plot, sp::Subplot)
 
     # update alphas
     for asym in (:linealpha, :markeralpha, :fillalpha)
-        if plotattributes[asym] == nothing
+        if plotattributes[asym] === nothing
             plotattributes[asym] = plotattributes[:seriesalpha]
         end
     end
-    if plotattributes[:markerstrokealpha] == nothing
+    if plotattributes[:markerstrokealpha] === nothing
         plotattributes[:markerstrokealpha] = plotattributes[:markeralpha]
     end
 
diff --git a/src/axes.jl b/src/axes.jl
index 8ef97f7e..66a42793 100644
--- a/src/axes.jl
+++ b/src/axes.jl
@@ -67,7 +67,7 @@ function process_axis_arg!(plotattributes::KW, arg, letter = "")
     elseif T <: AVec
         plotattributes[Symbol(letter,:ticks)] = arg
 
-    elseif arg == nothing
+    elseif arg === nothing
         plotattributes[Symbol(letter,:ticks)] = []
 
     elseif T <: Bool || arg in _allShowaxisArgs
@@ -166,7 +166,7 @@ function optimal_ticks_and_labels(sp::Subplot, axis::Axis, ticks = nothing)
     # or DateTime) is chosen based on the time span between amin and amax
     # rather than on the input format
     # TODO: maybe: non-trivial scale (:ln, :log2, :log10) for date/datetime
-    if ticks == nothing && scale == :identity
+    if ticks === nothing && scale == :identity
         if axis[:formatter] == dateformatter
             # optimize_datetime_ticks returns ticks and labels(!) based on
             # integers/floats corresponding to the DateTime type. Thus, the axes
@@ -184,7 +184,7 @@ function optimal_ticks_and_labels(sp::Subplot, axis::Axis, ticks = nothing)
     end
 
     # get a list of well-laid-out ticks
-    if ticks == nothing
+    if ticks === nothing
         scaled_ticks = optimize_ticks(
             sf(amin),
             sf(amax);
@@ -399,7 +399,7 @@ function expand_extrema!(sp::Subplot, plotattributes::KW)
 
     # expand for fillrange
     fr = plotattributes[:fillrange]
-    if fr == nothing && plotattributes[:seriestype] == :bar
+    if fr === nothing && plotattributes[:seriestype] == :bar
         fr = 0.0
     end
     if fr != nothing && !all3D(plotattributes)
@@ -419,7 +419,7 @@ function expand_extrema!(sp::Subplot, plotattributes::KW)
         data = plotattributes[dsym]
 
         bw = plotattributes[:bar_width]
-        if bw == nothing
+        if bw === nothing
             bw = plotattributes[:bar_width] = _bar_width * ignorenan_minimum(filter(x->x>0,diff(sort(data))))
         end
         axis = sp.attr[Symbol(dsym, :axis)]
diff --git a/src/backends.jl b/src/backends.jl
index a95b2dd2..01226e78 100644
--- a/src/backends.jl
+++ b/src/backends.jl
@@ -77,7 +77,7 @@ text_size(lab::AbstractString, sz::Number, rot::Number = 0) = text_size(length(l
 # account for the size/length/rotation of tick labels
 function tick_padding(sp::Subplot, axis::Axis)
     ticks = get_ticks(sp, axis)
-    if ticks == nothing
+    if ticks === nothing
         0mm
     else
         vals, labs = ticks
diff --git a/src/backends/gr.jl b/src/backends/gr.jl
index 691daa83..dd21e3a6 100644
--- a/src/backends/gr.jl
+++ b/src/backends/gr.jl
@@ -620,7 +620,7 @@ end
 
 function gr_set_gradient(series::Series)
     color = gr_get_color(series)
-    color !== nothing && gr_set_gradient(color)
+    color !=== nothing && gr_set_gradient(color)
 end
 
 function gr_get_color(series::Series)
@@ -1509,7 +1509,7 @@ function gr_display(sp::Subplot{GRBackend}, w, h, viewport_canvas)
                 lc = get_linecolor(series, clims)
                 gr_set_line(get_linewidth(series), get_linestyle(series), lc) #, series[:linealpha])
 
-                if (st == :shape || series[:fillrange] != nothing) && series[:ribbon] == nothing
+                if (st == :shape || series[:fillrange] != nothing) && series[:ribbon] === nothing
                     fc = get_fillcolor(series, clims)
                     gr_set_fill(fc) #, series[:fillalpha])
                     l, r = xpos-0.07, xpos-0.01
@@ -1526,7 +1526,7 @@ function gr_display(sp::Subplot{GRBackend}, w, h, viewport_canvas)
 
                 if st in (:path, :straightline)
                     gr_set_transparency(lc, get_linealpha(series))
-                    if series[:fillrange] == nothing || series[:ribbon] != nothing
+                    if series[:fillrange] === nothing || series[:ribbon] != nothing
                         GR.polyline([xpos - 0.07, xpos - 0.01], [ypos, ypos])
                     else
                         GR.polyline([xpos - 0.07, xpos - 0.01], [ypos+0.4dy, ypos+0.4dy])
diff --git a/src/backends/plotly.jl b/src/backends/plotly.jl
index bdad392a..78df1a84 100644
--- a/src/backends/plotly.jl
+++ b/src/backends/plotly.jl
@@ -827,7 +827,7 @@ function plotly_html_head(plt::Plot)
 end
 
 function plotly_html_body(plt, style = nothing)
-    if style == nothing
+    if style === nothing
         w, h = plt[:size]
         style = "width:$(w)px;height:$(h)px;"
     end
diff --git a/src/backends/pyplot.jl b/src/backends/pyplot.jl
index eec1e6ca..5751a43f 100644
--- a/src/backends/pyplot.jl
+++ b/src/backends/pyplot.jl
@@ -871,7 +871,7 @@ end
 function py_set_ticks(ax, ticks, letter)
     ticks == :auto && return
     axis = getproperty(ax, Symbol(letter,"axis"))
-    if ticks == :none || ticks == nothing || ticks == false
+    if ticks == :none || ticks === nothing || ticks == false
         kw = KW()
         for dir in (:top,:bottom,:left,:right)
             kw[dir] = kw[Symbol(:label,dir)] = false
@@ -978,7 +978,7 @@ function _before_layout_calcs(plt::Plot{PyPlotBackend})
     # update subplots
     for sp in plt.subplots
         ax = sp.o
-        if ax == nothing
+        if ax === nothing
             continue
         end
 
@@ -1186,7 +1186,7 @@ end
 # to fit ticks, tick labels, guides, colorbars, etc.
 function _update_min_padding!(sp::Subplot{PyPlotBackend})
     ax = sp.o
-    ax == nothing && return sp.minpad
+    ax === nothing && return sp.minpad
     plotbb = py_bbox(ax)
 
     # TODO: this should initialize to the margin from sp.attr
@@ -1352,7 +1352,7 @@ end
 function _update_plot_object(plt::Plot{PyPlotBackend})
     for sp in plt.subplots
         ax = sp.o
-        ax == nothing && return
+        ax === nothing && return
         figw, figh = sp.plt[:size]
         figw, figh = figw*px, figh*px
         pcts = bbox_to_pcts(sp.plotarea, figw, figh)
diff --git a/src/components.jl b/src/components.jl
index 097aee19..4aa27043 100644
--- a/src/components.jl
+++ b/src/components.jl
@@ -568,7 +568,7 @@ mutable struct EachAnn
 end
 
 function Base.iterate(ea::EachAnn, i = 1)
-    if ea.anns == nothing || isempty(ea.anns.strs) || i > length(ea.y)
+    if ea.anns === nothing || isempty(ea.anns.strs) || i > length(ea.y)
         return nothing
     end
 
diff --git a/src/plot.jl b/src/plot.jl
index 2c2ecd48..4352403a 100644
--- a/src/plot.jl
+++ b/src/plot.jl
@@ -4,7 +4,7 @@ mutable struct CurrentPlot
 end
 const CURRENT_PLOT = CurrentPlot(nothing)
 
-isplotnull() = CURRENT_PLOT.nullableplot == nothing
+isplotnull() = CURRENT_PLOT.nullableplot === nothing
 
 """
     current()
diff --git a/src/recipes.jl b/src/recipes.jl
index 9227f189..1424c6e5 100644
--- a/src/recipes.jl
+++ b/src/recipes.jl
@@ -239,7 +239,7 @@ end
 @recipe function f(::Type{Val{:sticks}}, x, y, z)
     n = length(x)
     fr = plotattributes[:fillrange]
-    if fr == nothing
+    if fr === nothing
         sp = plotattributes[:subplot]
         yaxis = sp[:yaxis]
         fr = if yaxis[:scale] == :identity
@@ -321,7 +321,7 @@ end
 
     x := newx
     y := newy
-    if z == nothing
+    if z === nothing
         seriestype := :path
     else
         seriestype := :path3d
@@ -357,7 +357,7 @@ end
 
     # compute half-width of bars
     bw = plotattributes[:bar_width]
-    hw = if bw == nothing
+    hw = if bw === nothing
         if nx > 1
             0.5*_bar_width*ignorenan_minimum(filter(x->x>0, diff(procx)))
         else
@@ -369,7 +369,7 @@ end
 
     # make fillto a vector... default fills to 0
     fillto = plotattributes[:fillrange]
-    if fillto == nothing
+    if fillto === nothing
         fillto = 0
     end
     if (yscale in _logScales) && !all(_is_positive, fillto)
@@ -491,7 +491,7 @@ end
 
 @recipe function f(::Type{Val{:barbins}}, x, y, z)
     edge, weights, xscale, yscale, baseline = _preprocess_binlike(plotattributes, x, y)
-    if (plotattributes[:bar_width] == nothing)
+    if (plotattributes[:bar_width] === nothing)
         bar_width := diff(edge)
     end
     x := _bin_centers(edge)
@@ -667,7 +667,7 @@ end
 function _make_hist(vs::NTuple{N,AbstractVector}, binning; normed = false, weights = nothing) where N
     localvs = _filternans(vs)
     edges = _hist_edges(localvs, binning)
-    h = float( weights == nothing ?
+    h = float( weights === nothing ?
         StatsBase.fit(StatsBase.Histogram, localvs, edges, closed = :left) :
         StatsBase.fit(StatsBase.Histogram, localvs, StatsBase.Weights(weights), edges, closed = :left)
     )
diff --git a/src/utils.jl b/src/utils.jl
index 666c878d..0415664c 100644
--- a/src/utils.jl
+++ b/src/utils.jl
@@ -26,7 +26,7 @@ function histogramHack(; kw...)
   plotattributes[:x] = midpoints
   plotattributes[:y] = float(counts)
   plotattributes[:seriestype] = :bar
-  plotattributes[:fillrange] = plotattributes[:fillrange] == nothing ? 0.0 : plotattributes[:fillrange]
+  plotattributes[:fillrange] = plotattributes[:fillrange] === nothing ? 0.0 : plotattributes[:fillrange]
   plotattributes
 end
 
@@ -38,7 +38,7 @@ function barHack(; kw...)
   plotattributes = KW(kw)
   midpoints = plotattributes[:x]
   heights = plotattributes[:y]
-  fillrange = plotattributes[:fillrange] == nothing ? 0.0 : plotattributes[:fillrange]
+  fillrange = plotattributes[:fillrange] === nothing ? 0.0 : plotattributes[:fillrange]
 
   # estimate the edges
   dists = diff(midpoints) * 0.5
@@ -81,7 +81,7 @@ function sticksHack(; kw...)
   # these are the line vertices
   x = Float64[]
   y = Float64[]
-  fillrange = plotattributesLine[:fillrange] == nothing ? 0.0 : plotattributesLine[:fillrange]
+  fillrange = plotattributesLine[:fillrange] === nothing ? 0.0 : plotattributesLine[:fillrange]
 
   # calculate the vertices
   yScatter = plotattributesScatter[:y]
@@ -194,7 +194,7 @@ end
 
 function iter_segments(series::Series)
     x, y, z = series[:x], series[:y], series[:z]
-    if x == nothing
+    if x === nothing
         return UnitRange{Int}[]
     elseif has_attribute_segments(series)
         if series[:seriestype] in (:scatter, :scatter3d)
@@ -478,7 +478,7 @@ function make_fillrange_from_ribbon(kw::KW)
     rib1, rib2 = -first(rib), last(rib)
     # kw[:ribbon] = nothing
     kw[:fillrange] = make_fillrange_side(y, rib1), make_fillrange_side(y, rib2)
-    (get(kw, :fillalpha, nothing) == nothing) && (kw[:fillalpha] = 0.5)
+    (get(kw, :fillalpha, nothing) === nothing) && (kw[:fillalpha] = 0.5)
 end
 
 #turn tuple of fillranges to one path
@@ -560,18 +560,18 @@ function colorbar_style(series::Series)
     elseif iscontour(series)
         cbar_lines
     elseif series[:seriestype] ∈ (:heatmap,:surface) ||
-            any(series[z] !== nothing for z ∈ [:marker_z,:line_z,:fill_z])
+            any(series[z] !=== nothing for z ∈ [:marker_z,:line_z,:fill_z])
         cbar_gradient
     else
         nothing
     end
 end
 
-hascolorbar(series::Series) = colorbar_style(series) !== nothing
+hascolorbar(series::Series) = colorbar_style(series) !=== nothing
 hascolorbar(sp::Subplot) = sp[:colorbar] != :none && any(hascolorbar(s) for s in series_list(sp))
 
 iscontour(series::Series) = series[:seriestype] == :contour
-isfilledcontour(series::Series) = iscontour(series) && series[:fillrange] !== nothing
+isfilledcontour(series::Series) = iscontour(series) && series[:fillrange] !=== nothing
 
 function contour_levels(series::Series, clims)
     iscontour(series) || error("Not a contour series")
@@ -602,7 +602,7 @@ for comp in (:line, :fill, :marker)
         function $get_compcolor(series, cmin::Real, cmax::Real, i::Int = 1)
             c = series[$Symbol($compcolor)]
             z = series[$Symbol($comp_z)]
-            if z == nothing
+            if z === nothing
                 isa(c, ColorGradient) ? c : plot_color(_cycle(c, i))
             else
                 grad = isa(c, ColorGradient) ? c : cgrad()
@@ -613,7 +613,7 @@ for comp in (:line, :fill, :marker)
         $get_compcolor(series, clims, i::Int = 1) = $get_compcolor(series, clims[1], clims[2], i)
 
         function $get_compcolor(series, i::Int = 1)
-            if series[$Symbol($comp_z)] == nothing
+            if series[$Symbol($comp_z)] === nothing
                 $get_compcolor(series, 0, 1, i)
             else
                 $get_compcolor(series, get_clims(series[:subplot]), i)
diff --git a/test/imgcomp.jl b/test/imgcomp.jl
index 206b8d50..1aa4ceee 100644
--- a/test/imgcomp.jl
+++ b/test/imgcomp.jl
@@ -64,7 +64,7 @@ function image_comparison_tests(pkg::Symbol, idx::Int; debug = false, popup = is
 
     # now we have the fn (if any)... do the comparison
     # @show reffn
-    if reffn == nothing
+    if reffn === nothing
         reffn = newfn
     end
     # @show reffn
@@ -98,7 +98,7 @@ function image_comparison_facts(pkg::Symbol;
                                 tol = 1e-2)     # acceptable error (percent)
   for i in 1:length(Plots._examples)
     i in skip && continue
-    if only == nothing || i in only
+    if only === nothing || i in only
       @test image_comparison_tests(pkg, i, debug=debug, sigma=sigma, tol=tol) |> success == true
     end
   end