diff --git a/src/Mod/Surface/App/Blending/FeatureBlendCurve.cpp b/src/Mod/Surface/App/Blending/FeatureBlendCurve.cpp
index 1c481cd6fa..669180856b 100644
--- a/src/Mod/Surface/App/Blending/FeatureBlendCurve.cpp
+++ b/src/Mod/Surface/App/Blending/FeatureBlendCurve.cpp
@@ -158,18 +158,15 @@ double FeatureBlendCurve::RelativeToRealParameters(double relativeValue, double
 void FeatureBlendCurve::onChanged(const App::Property *prop)
 {
     if (prop == &StartContinuity) {
-        auto changedStartProp = dynamic_cast<const App::PropertyInteger *>(prop);
-
-        if (changedStartProp->getValue() > (maxDegree - 2 - EndContinuity.getValue())) {
-
-            StartContinuity.setValue(maxDegree - 2 - EndContinuity.getValue());
+        long maxValue = maxDegree - 2 - EndContinuity.getValue();
+        if (StartContinuity.getValue() > maxValue) {
+            StartContinuity.setValue(maxValue);
         }
     }
     else if (prop == &EndContinuity) {
-        auto changedEndProp = dynamic_cast<const App::PropertyInteger *>(prop);
-
-        if (changedEndProp->getValue() > (maxDegree - 2 - StartContinuity.getValue())) {
-            EndContinuity.setValue(maxDegree - 2 - StartContinuity.getValue());
+        long maxValue = maxDegree - 2 - StartContinuity.getValue();
+        if (EndContinuity.getValue() > maxValue) {
+            EndContinuity.setValue(maxValue);
         }
     }
     if (prop == &StartContinuity || prop == &StartParameter || prop == &StartSize || prop == &EndContinuity || prop == &EndParameter || prop == &EndSize) {
diff --git a/src/Mod/Surface/App/Blending/FeatureBlendCurve.h b/src/Mod/Surface/App/Blending/FeatureBlendCurve.h
index a792e83bca..9ea76f1851 100644
--- a/src/Mod/Surface/App/Blending/FeatureBlendCurve.h
+++ b/src/Mod/Surface/App/Blending/FeatureBlendCurve.h
@@ -63,7 +63,6 @@ public:
 private:
     BlendPoint GetBlendPoint(App::PropertyLinkSub &link, App::PropertyFloatConstraint &param, App::PropertyIntegerConstraint &Continuity);
     double RelativeToRealParameters(double, double, double);
-    bool lockOnChangeMutex{false};
 
 protected:
     void onChanged(const App::Property *prop) override;