diff --git a/quickstats/components/workspaces/xml_ws_modifier.py b/quickstats/components/workspaces/xml_ws_modifier.py
index e1a6396f2aaac69f045ab0c452df80ef4d206189..82546c9d6cea402319aec947feb75b285f33d1d8 100644
--- a/quickstats/components/workspaces/xml_ws_modifier.py
+++ b/quickstats/components/workspaces/xml_ws_modifier.py
@@ -611,7 +611,7 @@ class XMLWSModifier(XMLWSBase):
                 self.stdout.warning(f"The nuisance parameter {nuis_name} no longer exists in "
                                     "the new workspace. It will be removed from the new ModelConfig.")
                 continue
-            if nuis.isConstant():
+            if nuis.isConstant() and nuis not in pois:
                 self.stdout.warning(f"The nuisace parameter {nuis_name} is initialized as a constant. "
                                     "It will be floated in the new workspace.")
                 nuis.setConstant(False)