diff --git a/test/render.jl b/test/render.jl
index 6adf24e..d41b047 100644
--- a/test/render.jl
+++ b/test/render.jl
@@ -80,8 +80,8 @@ end
         mode = BeforeAfterFull()
         for (x, xname) in items
             # @info "Types" x=typeof(x) mode=mode
-            @test_reference joinpath(refdir, "BeforeAfterFull", "$(xname)_new.txt") @io2str render(::IO, mode, x[2])
-            @test_reference joinpath(refdir, "BeforeAfterFull", "$(xname)_compare.txt") @io2str render(::IO, mode, x...)
+            @test_reference joinpath(refdir, "BeforeAfterFull", "$(xname)_new.txt") @io2str(render(::IO, mode, x[2])) by=string_check
+            @test_reference joinpath(refdir, "BeforeAfterFull", "$(xname)_compare.txt") @io2str(render(::IO, mode, x...)) by=string_check
         end
     end
 
@@ -89,8 +89,8 @@ end
         mode = BeforeAfterLimited()
         for (x, xname) in items
             # @info "Types" x=typeof(x) mode=mode
-            @test_reference joinpath(refdir, "BeforeAfterLimited", "$(xname)_new.txt") @io2str render(::IO, mode, x[2])
-            @test_reference joinpath(refdir, "BeforeAfterLimited", "$(xname)_compare.txt") @io2str render(::IO, mode, x...)
+            @test_reference joinpath(refdir, "BeforeAfterLimited", "$(xname)_new.txt") @io2str(render(::IO, mode, x[2])) by=string_check
+            @test_reference joinpath(refdir, "BeforeAfterLimited", "$(xname)_compare.txt") @io2str(render(::IO, mode, x...)) by=string_check
         end
     end
 
@@ -102,8 +102,8 @@ end
                            (str3, "str3"),
                         )
             # @info "Types" x=typeof(x) mode=mode
-            @test_reference joinpath(refdir, "Diff", "$(xname)_new.txt") @io2str render(::IO, mode, x[2])
-            @test_reference joinpath(refdir, "Diff", "$(xname)_compare.txt") @io2str render(::IO, mode, x...)
+            @test_reference joinpath(refdir, "Diff", "$(xname)_new.txt") @io2str(render(::IO, mode, x[2])) by=string_check
+            @test_reference joinpath(refdir, "Diff", "$(xname)_compare.txt") @io2str(render(::IO, mode, x...)) by=string_check
         end
     end
 
@@ -117,8 +117,8 @@ end
                         #    (img3d_1, "img3d_1")
                         )
             # @info "Types" x=typeof(x) mode=mode
-            @test_reference joinpath(refdir, "BeforeAfterImage", "$(xname)_new.txt") @io2str render(::IO, mode, x[2])
-            @test_reference joinpath(refdir, "BeforeAfterImage", "$(xname)_compare.txt") @io2str render(::IO, mode, x...)
+            @test_reference joinpath(refdir, "BeforeAfterImage", "$(xname)_new.txt") @io2str(render(::IO, mode, x[2])) by=string_check
+            @test_reference joinpath(refdir, "BeforeAfterImage", "$(xname)_compare.txt") @io2str(render(::IO, mode, x...)) by=string_check
         end
     end
 
diff --git a/test/testutils.jl b/test/testutils.jl
index 8208b14..216b928 100644
--- a/test/testutils.jl
+++ b/test/testutils.jl
@@ -1 +1,18 @@
 strip_summary(content::String) = join(split(content, "\n")[2:end], "\n")
+
+function string_check(ref, actual)
+    patterns = [
+        # Julia v1.6
+        "Normed{UInt8,8}" => "N0f8",
+
+        # https://github.com/JuliaGraphics/ColorTypes.jl/pull/206
+        # r"Gray{\w+}\(([\w\.]+)\)" => s"\1",
+        # r"RGB{\w+}\(([\w\.,]+)\)" => s"RGB(\1)",
+    ]
+
+    for p in patterns
+        actual = replace(actual, p)
+        ref = replace(ref, p)
+    end
+    isequal(ref, actual)
+end