diff --git a/docs/src/mappings/hakank.md b/docs/src/mappings/hakank.md
index 975363d..1691754 100644
--- a/docs/src/mappings/hakank.md
+++ b/docs/src/mappings/hakank.md
@@ -8,7 +8,7 @@ All the constraints that are currently defined in [hakank's constraints_utils.jl
 * `decreasing_strict`: `Strictly(Decreasing)`
 * `all_different_except_c`: `AllDifferentExceptConstants`
 * `count_ctr`: `Count` (except for operators)
-* `count_ctr2`: `CountDistinct` (except for operators)
+* `count_ctr2`: `MOI.CountDistinct` (except for operators)
 * `global_cardinality_count`: `Count`
 * `either_eq`: `Disjunction`
 * `is_member_of`: `Domain` and `Membership`
@@ -29,4 +29,4 @@ All the constraints that are currently defined in [hakank's constraints_utils.jl
 * `lex_less_eq`: `LexicographicallyLessThan`
 * `among`: `Count`
 
-Functions: TODO
\ No newline at end of file
+Functions: TODO
diff --git a/docs/src/reference/sets.md b/docs/src/reference/sets.md
index b2b29f0..d8e79fa 100644
--- a/docs/src/reference/sets.md
+++ b/docs/src/reference/sets.md
@@ -64,7 +64,6 @@ KnapsackValueType
 ```@docs
 Count
 CountCompare
-CountDistinct
 ```
 
 ### Global cardinality
diff --git a/src/Test/test_countdistinct.jl b/src/Test/test_countdistinct.jl
index da516e9..1061dea 100644
--- a/src/Test/test_countdistinct.jl
+++ b/src/Test/test_countdistinct.jl
@@ -4,7 +4,7 @@ function test_countdistinct_vectorofvariables(
 ) where {T <: Real}
     @MOIT.requires MOI.supports_constraint(model, MOI.VariableIndex, MOI.Integer) # x1, x2, x3, x4
     @MOIT.requires MOI.supports_constraint(model, MOI.VariableIndex, MOI.EqualTo{T}) # c1, c2, c3
-    @MOIT.requires MOI.supports_constraint(model, MOI.VectorOfVariables, CP.CountDistinct) # c4
+    @MOIT.requires MOI.supports_constraint(model, MOI.VectorOfVariables, MOI.CountDistinct) # c4
 
     x1, _ = MOI.add_constrained_variable(model, MOI.Integer())
     x2, _ = MOI.add_constrained_variable(model, MOI.Integer())
@@ -15,7 +15,7 @@ function test_countdistinct_vectorofvariables(
     c2 = MOI.add_constraint(model, x2, MOI.EqualTo(1))
     c3 = MOI.add_constraint(model, x3, MOI.EqualTo(2))
 
-    c4 = MOI.add_constraint(model, MOI.VectorOfVariables([x4, x1, x2, x3]), CP.CountDistinct(3))
+    c4 = MOI.add_constraint(model, MOI.VectorOfVariables([x4, x1, x2, x3]), MOI.CountDistinct(4))
 
     @test MOI.is_valid(model, x1)
     @test MOI.is_valid(model, x2)
@@ -57,7 +57,7 @@ function test_countdistinct_vectoraffinefunction(
 ) where {T <: Real}
     @MOIT.requires MOI.supports_constraint(model, MOI.VariableIndex, MOI.Integer) # x1, x2, x3, x4
     @MOIT.requires MOI.supports_constraint(model, MOI.ScalarAffineFunction{T}, MOI.EqualTo{T}) # c1, c2, c3
-    @MOIT.requires MOI.supports_constraint(model, MOI.VectorAffineFunction{T}, CP.CountDistinct) # c4
+    @MOIT.requires MOI.supports_constraint(model, MOI.VectorAffineFunction{T}, MOI.CountDistinct) # c4
 
     x1, _ = MOI.add_constrained_variable(model, MOI.Integer())
     x2, _ = MOI.add_constrained_variable(model, MOI.Integer())
@@ -68,7 +68,7 @@ function test_countdistinct_vectoraffinefunction(
     c2 = MOI.add_constraint(model, one(T) * x2, MOI.EqualTo(1))
     c3 = MOI.add_constraint(model, one(T) * x3, MOI.EqualTo(2))
 
-    c4 = MOI.add_constraint(model, MOIU.vectorize(one(T) .* [x4, x1, x2, x3]), CP.CountDistinct(3))
+    c4 = MOI.add_constraint(model, MOIU.vectorize(one(T) .* [x4, x1, x2, x3]), MOI.CountDistinct(4))
 
     @test MOI.is_valid(model, x1)
     @test MOI.is_valid(model, x2)
diff --git a/src/sets_count.jl b/src/sets_count.jl
index bd968e1..e35a816 100644
--- a/src/sets_count.jl
+++ b/src/sets_count.jl
@@ -253,31 +253,7 @@ end
 
 MOI.dimension(set::CountCompare) = 2 * set.dimension + 1
 
-"""
-    CountDistinct(dimension::Int)
-
-The first variable in the set is forced to be the number of distinct values in
-the rest of the expressions.
-
-This is a relaxed version of `MOI.AllDifferent`; it encodes an `MOI.AllDifferent`
-constraint when the first variable is the number of variables in the set.
-
-Also called `nvalues`.
-
-## Example
-
-    [x, y, z] in CountDistinct(3)
-    # x = 1 if y == z, x = 2 if y != z
-"""
-struct CountDistinct <: MOI.AbstractVectorSet
-    dimension::Int
-end
-
-MOI.dimension(set::CountDistinct) = set.dimension + 1
-
 # isbits types, nothing to copy
-function copy(
-    set::Union{CountCompare, CountDistinct},
-)
+function copy(set::CountCompare)
     return set
 end
diff --git a/test/sets.jl b/test/sets.jl
index da0487a..995b2e6 100644
--- a/test/sets.jl
+++ b/test/sets.jl
@@ -24,11 +24,9 @@
     # Just a dimension.
     @testset "$(S)" for S in [
         CP.AllEqual,
-        MOI.AllDifferent,
         CP.SymmetricAllDifferent,
         CP.Membership,
         CP.ElementVariableArray,
-        CP.CountDistinct,
         CP.Inverse,
         CP.Contiguity,
         CP.LexicographicallyLessThan,
@@ -54,7 +52,6 @@
 
         if S in [
             CP.AllEqual,
-            MOI.AllDifferent,
             CP.SymmetricAllDifferent,
             CP.Membership,
             CP.Contiguity,
@@ -64,7 +61,6 @@
             @test MOI.dimension(S(2)) == 2
             @test MOI.dimension(S(3)) == 3
         elseif S in [
-            CP.CountDistinct,
             CP.MinimumAmong,
             CP.MaximumAmong,
             CP.ArgumentMinimumAmong,