diff --git a/gotools-core/src/geometry/BoundedUtils.C b/gotools-core/src/geometry/BoundedUtils.C
index 5d5b19323..4baede2fb 100644
--- a/gotools-core/src/geometry/BoundedUtils.C
+++ b/gotools-core/src/geometry/BoundedUtils.C
@@ -114,6 +114,9 @@ BoundedUtils::intersectWithSurface(CurveOnSurface& curve,
   double int_tol = 0.1*epsge; //1e-06;
   shared_ptr<const ParamSurface> under_sf = bounded_surf.underlyingSurface();
   double ptol = getParEps(epsge, under_sf.get());
+  if (std::isnan(ptol)) {
+    THROW("Parametric epsilon is nan, suspecting unbounded domain, not supported");
+  }
   int_tol = ptol;
   double tdel = curve.endparam() - curve.startparam();
   double delfac = 0.01;
diff --git a/intersections/src/Coincidence.C b/intersections/src/Coincidence.C
index 362b39283..8a2ab9811 100644
--- a/intersections/src/Coincidence.C
+++ b/intersections/src/Coincidence.C
@@ -527,6 +527,14 @@ int checkCoincide(ParamCurveInt *curve,
     if (fabs(other_end - other_start) < tol->getRelParRes())
 	return 0;  // Probably a closed curve
   
+    // With both end points equal we then check if curves are both linear. Needed
+    // to handle cases with practically unbounded domains (cylinders, planes, cones).
+    bool curve_linear = (curve->getParamCurve()->instanceType() == Class_Line);
+    bool other_linear = (other->getParamCurve()->instanceType() == Class_Line);
+    if (curve_linear && other_linear) {
+        return 1;
+    }
+
 //    double delta = 0.9*eps*eps;
     // double init_dist = std::max(pnt1.dist(pnt2), pnt3.dist(pnt4));
     //double delta = (init_dist < 0.9*toler) ? 0.9*toler : toler;