diff --git a/Project.toml b/Project.toml
index 220b83b..bb8971b 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "ITensorBase"
 uuid = "4795dd04-0d67-49bb-8f44-b89c448a1dc7"
 authors = ["ITensor developers <support@itensor.org> and contributors"]
-version = "0.1.17"
+version = "0.1.18"
 
 [deps]
 Accessors = "7d9f7c33-5ae7-4f3b-8dc6-eff91059b697"
diff --git a/src/index.jl b/src/index.jl
index 39f145a..1e280e6 100644
--- a/src/index.jl
+++ b/src/index.jl
@@ -10,14 +10,24 @@ using NamedDimsArrays:
   randname,
   setname
 
-tagsstring(tags::Dict{String,String}) = string(tags)
+tagpairstring(pair::Pair) = repr(first(pair)) * "=>" * repr(last(pair))
+function tagsstring(tags::Dict{String,String})
+  tagpairs = sort(collect(tags); by=first)
+  tagpair1, tagpair_rest = Iterators.peel(tagpairs)
+  return mapreduce(*, tagpair_rest; init=tagpairstring(tagpair1)) do tagpair
+    return "," * tagpairstring(tagpair)
+  end
+end
 
-@kwdef struct IndexName <: AbstractName
-  id::UInt64 = rand(UInt64)
-  tags::Dict{String,String} = Dict{String,String}()
-  plev::Int = 0
+struct IndexName <: AbstractName
+  id::UInt64
+  tags::Dict{String,String}
+  plev::Int
+end
+function IndexName(; id::UInt64=rand(UInt64), tags=Dict{String,String}(), plev::Int=0)
+  return IndexName(id, Dict{String,String}(tags), plev)
 end
-NamedDimsArrays.randname(n::IndexName) = IndexName(; tags=tags(n), plev=plev(n))
+NamedDimsArrays.randname(n::IndexName) = IndexName()
 
 id(n::IndexName) = n.id
 tags(n::IndexName) = n.tags
@@ -47,7 +57,7 @@ sim(n::IndexName) = randname(n)
 
 function Base.show(io::IO, i::IndexName)
   idstr = "id=$(id(i) % 1000)"
-  tagsstr = !isempty(tags(i)) ? "|\"$(tagsstring(tags(i)))\"" : ""
+  tagsstr = !isempty(tags(i)) ? "|$(tagsstring(tags(i)))" : ""
   primestr = primestring(plev(i))
   str = "IndexName($(idstr)$(tagsstr))$(primestr)"
   print(io, str)
@@ -125,7 +135,7 @@ end
 function Base.show(io::IO, i::Index)
   lenstr = "length=$(dename(length(i)))"
   idstr = "|id=$(id(i) % 1000)"
-  tagsstr = !isempty(tags(i)) ? "|\"$(tagsstring(tags(i)))\"" : ""
+  tagsstr = !isempty(tags(i)) ? "|$(tagsstring(tags(i)))" : ""
   primestr = primestring(plev(i))
   str = "Index($(lenstr)$(idstr)$(tagsstr))$(primestr)"
   print(io, str)
diff --git a/test/test_basics.jl b/test/test_basics.jl
index 01b5612..9b5dd11 100644
--- a/test/test_basics.jl
+++ b/test/test_basics.jl
@@ -60,6 +60,28 @@ using Test: @test, @test_broken, @test_throws, @testset
     @test dename(i) == 1:2
     @test plev(i) == 0
     @test length(tags(i)) == 0
+
+    for i in (
+      Index(2; tags=Dict(["X" => "Y"])),
+      Index(2; tags=["X" => "Y"]),
+      Index(2; tags=("X" => "Y",)),
+      Index(2; tags="X" => "Y"),
+    )
+      @test Int(length(i)) == 2
+      @test hastag(i, "X")
+      @test gettag(i, "X") == "Y"
+      @test plev(i) == 0
+      @test length(tags(i)) == 1
+    end
+  end
+  @testset "show" begin
+    id = rand(UInt64)
+    i = Index(2; id)
+    @test sprint(show, "text/plain", i) == "Index(length=2|id=$(id % 1000))"
+
+    id = rand(UInt64)
+    i = Index(2; id, tags=["X" => "Y"])
+    @test sprint(show, "text/plain", i) == "Index(length=2|id=$(id % 1000)|\"X\"=>\"Y\")"
   end
   @testset "delta" begin
     i, j = Index.((2, 2))