diff --git a/src/Mod/Fem/Gui/ViewProviderFemConstraint.cpp b/src/Mod/Fem/Gui/ViewProviderFemConstraint.cpp
index c9eab5060..e06ae0240 100644
--- a/src/Mod/Fem/Gui/ViewProviderFemConstraint.cpp
+++ b/src/Mod/Fem/Gui/ViewProviderFemConstraint.cpp
@@ -24,6 +24,7 @@
 #include "PreCompiled.h"
 
 #ifndef _PreComp_
+# include <Standard_math.hxx>
 # include <QApplication>
 # include <Inventor/nodes/SoSeparator.h>
 # include <Inventor/nodes/SoBaseColor.h>
@@ -74,7 +75,7 @@ ViewProviderFemConstraint::ViewProviderFemConstraint()
     pMaterials = new SoMaterial();
     pMaterials->ref();
     pMaterials->diffuseColor.setValue(1.0f, 0.0f, 0.2f);
-    pMaterials->transparency.setValue(0.1);
+    pMaterials->transparency.setValue(0.1f);
     //pMaterials->ambientColor.setValue(0.8f, 0.8f, 0.8f);
     //pMaterials->shininess.setValue(1.0);