diff --git a/base/arrayshow.jl b/base/arrayshow.jl
index e3028cd65dfe0..7d63375ab3549 100644
--- a/base/arrayshow.jl
+++ b/base/arrayshow.jl
@@ -40,7 +40,7 @@ centered cdot, used in printing of structural zeros of structured matrices.
 Accept keyword args `c` for alternate single character marker.
 """
 function replace_with_centered_mark(s::AbstractString;c::AbstractChar = '⋅')
-    N = length(s)
+    N = textwidth(ANSIIterator(s))
     return join(setindex!([" " for i=1:N],string(c),ceil(Int,N/2)))
 end
 
diff --git a/test/show.jl b/test/show.jl
index 459a5d5ba3abb..5e5583135915b 100644
--- a/test/show.jl
+++ b/test/show.jl
@@ -2379,6 +2379,10 @@ Base.show(io::IO, ces::⛵) = Base.print(io, '⛵')
 @test Base.alignment(IOContext(IOBuffer(), :color=>true), ColoredLetter()) == (0, 1)
 @test Base.alignment(IOContext(IOBuffer(), :color=>false), ColoredLetter()) == (0, 1)
 
+# spacing around dots in Diagonal, etc:
+redminusthree = sprint((io, x) -> printstyled(io, x, color=:red), "-3", context=stdout)
+@test Base.replace_with_centered_mark(redminusthree) == Base.replace_with_centered_mark("-3")
+
 # `show` implementations for `Method`
 let buf = IOBuffer()