diff --git a/src/OpenFOAM/global/unitConversion/unitConversion.H b/src/OpenFOAM/global/unitConversion/unitConversion.H
index 10263f2a61d90403a8f2f354eb11ca01169bd863..6c4241d2062111bb87d6fbf5fdcef9defb490953 100644
--- a/src/OpenFOAM/global/unitConversion/unitConversion.H
+++ b/src/OpenFOAM/global/unitConversion/unitConversion.H
@@ -44,13 +44,15 @@ namespace Foam
 //- Conversion from degrees to radians
 inline constexpr scalar degToRad(const scalar deg) noexcept
 {
-    return (deg*Foam::constant::mathematical::pi/180.0);
+    //return (deg*Foam::constant::mathematical::pi/180.0);
+    return (deg*M_PI/180.0);
 }
 
 //- Conversion from radians to degrees
 inline constexpr scalar radToDeg(const scalar rad) noexcept
 {
-    return (rad*180.0/Foam::constant::mathematical::pi);
+    //return (rad*180.0/Foam::constant::mathematical::pi);
+    return (rad*180.0/M_PI);
 }
 
 //- Conversion from atm to Pa
@@ -69,13 +71,15 @@ inline constexpr scalar paToAtm(const scalar pa) noexcept
 //- User literal for degrees to radians conversion (integers)
 inline constexpr scalar operator "" _deg(unsigned long long int deg) noexcept
 {
-    return (deg*Foam::constant::mathematical::pi/180.0);
+    //return (deg*Foam::constant::mathematical::pi/180.0);
+    return (deg*M_PI/180.0);
 }
 
 //- User literal for degrees to radians conversion (floats)
 inline constexpr scalar operator "" _deg(long double deg) noexcept
 {
-    return (deg*Foam::constant::mathematical::pi/180.0);
+    //return (deg*Foam::constant::mathematical::pi/180.0);
+    return (deg*M_PI/180.0);
 }