diff --git a/conda-recipe/meta.yaml b/conda-recipe/meta.yaml
index a13244afa0..318febc365 100644
--- a/conda-recipe/meta.yaml
+++ b/conda-recipe/meta.yaml
@@ -59,6 +59,7 @@ requirements:
         - fiatlux
         - frozendict  # needed for caching of data loading
         - curio >=1.0 # reportengine uses it but it's not in its dependencies
+        - scikit-learn = "^1.4.1"
 
 test:
     requires:
diff --git a/pyproject.toml b/pyproject.toml
index 0562e82f22..99904644c4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -69,6 +69,7 @@ pandas = "<2"
 numpy = "*"
 validobj = "*"
 prompt_toolkit = "*"
+scikit-learn = "^1.4.1"
 frozendict = "*"  # validphys: needed for caching of data loading
 # Reportengine (and its dependencies) need to be installed in a bit more manual way
 reportengine = { git = "https://github.com/NNPDF/reportengine", rev = "3bb2b1d"}
@@ -97,7 +98,6 @@ fiatlux = {version = "*", optional = true}
 # without lhapdf
 pdfflow = {version = "^1.2.1", optional = true}
 lhapdf-management = {version = "^0.5", optional = true}
-scikit-learn = "^1.4.1"
 
 # Optional dependencies
 [tool.poetry.extras]