diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 25556ce..17c6c01 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,7 +1,15 @@
 name: CI
 on:
-  - push
-  - pull_request
+  push:
+    branches:
+      - main
+    tags: '*'
+  pull_request:
+concurrency:
+  # Skip intermediate builds: always.
+  # Cancel intermediate builds: only if it is a pull request build.
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ startsWith(github.ref, 'refs/pull/') }}
 jobs:
   test:
     name: Julia ${{ matrix.version }} - ${{ matrix.os }} - ${{ matrix.arch }} - ${{ github.event_name }}
diff --git a/Project.toml b/Project.toml
index d5547d6..2ecc531 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "LocalSearchSolvers"
 uuid = "2b10edaa-728d-4283-ac71-07e312d6ccf3"
 authors = ["Jean-Francois Baffier"]
-version = "0.4.0"
+version = "0.4.1"
 
 [deps]
 CompositionalNetworks = "4b67e4b5-442d-4ef5-b760-3f5df3a57537"
diff --git a/src/LocalSearchSolvers.jl b/src/LocalSearchSolvers.jl
index f25ae40..9214b99 100644
--- a/src/LocalSearchSolvers.jl
+++ b/src/LocalSearchSolvers.jl
@@ -1,8 +1,5 @@
 module LocalSearchSolvers
 
-using Dictionaries: include
-using CompositionalNetworks: include
-using Constraints: include
 using Base.Threads
 using CompositionalNetworks
 using ConstraintDomains
diff --git a/src/constraint.jl b/src/constraint.jl
index 231ad8c..28b914d 100644
--- a/src/constraint.jl
+++ b/src/constraint.jl
@@ -50,4 +50,13 @@ Base.in(var::Int, c::Constraint) = var ∈ c.vars
 
 DOCSTRING
 """
-constraint(f, vars) = Constraint(f, collect(Int == Int32 ? map(Int,vars) : vars))
+function constraint(f, vars)
+    b1 = hasmethod(f, NTuple{1, Any}, (:X,))
+    b2 = hasmethod(f, NTuple{1, Any}, (:do_not_use_this_kwarg_name,))
+
+    g = f
+    if !b1 || b2
+        g = (x; X=nothing) -> f(x)
+    end
+    return Constraint(g, collect(Int == Int32 ? map(Int,vars) : vars))
+end