diff --git a/src/Model/HydraulicStructures/HydraulicStructures.py b/src/Model/HydraulicStructures/HydraulicStructures.py
index b4db6c3405e96ba4cb76ef696ffa9c6695a0b989..c56e27e3a902810667d11b503511cb626ccf96ff 100644
--- a/src/Model/HydraulicStructures/HydraulicStructures.py
+++ b/src/Model/HydraulicStructures/HydraulicStructures.py
@@ -200,7 +200,10 @@ class HydraulicStructure(SQLSubModel):
 
     @input_kp.setter
     def input_kp(self, input_kp):
-        self._input_kp = float(input_kp)
+        if input_kp is not None:
+            input_kp = float(input_kp)
+
+        self._input_kp = input_kp
         self._status.modified()
 
     @property