diff --git a/HISTORY.rst b/HISTORY.rst
index 1838ee4..6212720 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -4,7 +4,7 @@ History
 1.15 (unreleased)
 -----------------
 
-- Nothing changed yet.
+- Fix type error: #278
 
 
 1.14 (2024-11-12)
diff --git a/threedi_schematisation_editor/processing/alghorithms_inflow.py b/threedi_schematisation_editor/processing/alghorithms_inflow.py
index b71c584..4cbadf0 100644
--- a/threedi_schematisation_editor/processing/alghorithms_inflow.py
+++ b/threedi_schematisation_editor/processing/alghorithms_inflow.py
@@ -133,19 +133,19 @@ def initAlgorithm(self, config=None):
             )
         )
         storm_pref = QgsProcessingParameterNumber(
-            self.STORMWATER_SEWER_PREFERENCE, self.tr("Stormwater sewer preference [m]"), type=1, defaultValue=0.0
+            self.STORMWATER_SEWER_PREFERENCE, self.tr("Stormwater sewer preference [m]"), type=QgsProcessingParameterNumber.Double, defaultValue=0.0
         )
         storm_pref.setMinimum(0.0)
         storm_pref.setMetadata({"widget_wrapper": {"decimals": 2}})
         self.addParameter(storm_pref)
         sanitary_pref = QgsProcessingParameterNumber(
-            self.SANITARY_SEWER_PREFERENCE, self.tr("Sanitary sewer preference [m]"), type=1, defaultValue=0.0
+            self.SANITARY_SEWER_PREFERENCE, self.tr("Sanitary sewer preference [m]"), type=QgsProcessingParameterNumber.Double, defaultValue=0.0
         )
         sanitary_pref.setMinimum(0.0)
         sanitary_pref.setMetadata({"widget_wrapper": {"decimals": 2}})
         self.addParameter(sanitary_pref)
         search_distance = QgsProcessingParameterNumber(
-            self.SEARCH_DISTANCE, self.tr("Search distance"), type=1, defaultValue=10.0
+            self.SEARCH_DISTANCE, self.tr("Search distance"), type=QgsProcessingParameterNumber.Double, defaultValue=10.0
         )
         search_distance.setMinimum(0.01)
         search_distance.setMetadata({"widget_wrapper": {"decimals": 2}})
diff --git a/threedi_schematisation_editor/processing/algorithms_1d2d.py b/threedi_schematisation_editor/processing/algorithms_1d2d.py
index 5876c7b..115956e 100644
--- a/threedi_schematisation_editor/processing/algorithms_1d2d.py
+++ b/threedi_schematisation_editor/processing/algorithms_1d2d.py
@@ -64,7 +64,7 @@ def initAlgorithm(self, config=None):
             )
         )
 
-        offset_param = QgsProcessingParameterNumber(self.OFFSET_DISTANCE, self.tr("Distance (m)"), type=1)
+        offset_param = QgsProcessingParameterNumber(self.OFFSET_DISTANCE, self.tr("Distance (m)"), type=QgsProcessingParameterNumber.Double)
         offset_param.setMetadata({"widget_wrapper": {"decimals": 3}})
         self.addParameter(offset_param)
         self.addParameter(