diff --git a/src/ViewportWidget.cpp b/src/ViewportWidget.cpp
index 2750a25..a36951d 100644
--- a/src/ViewportWidget.cpp
+++ b/src/ViewportWidget.cpp
@@ -770,8 +770,8 @@ void ViewportWidget::drawSketch(const SketchFeature* sketch)
         if (pair.second == 1) {
             const gp_Pnt& center = pair.first;
             for (int i = 0; i < numSegments; ++i) {
-                float angle1 = (2.0f * qPi() * float(i)) / float(numSegments);
-                float angle2 = (2.0f * qPi() * float(i + 1)) / float(numSegments);
+                float angle1 = (2.0f * M_PI * float(i)) / float(numSegments);
+                float angle2 = (2.0f * M_PI * float(i + 1)) / float(numSegments);
 
                 float x1, y1, z1, x2, y2, z2;