diff --git a/.gitignore b/.gitignore
index 9f6cec7..5e870a9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,3 +16,4 @@
 /e6afb9cbae4064da8c3e69af3ff5c4629579c1d2.tar.gz
 /CuraEngine-3.5.1.tar.gz
 /CuraEngine-3.6.0.tar.gz
+/CuraEngine-4.0.0.tar.gz
diff --git a/CuraEngine-gcc9.patch b/CuraEngine-gcc9.patch
index 1c83271..67f704f 100644
--- a/CuraEngine-gcc9.patch
+++ b/CuraEngine-gcc9.patch
@@ -1,5 +1,5 @@
 diff --git a/src/layerPart.cpp b/src/layerPart.cpp
-index 80370fe..07d40f2 100644
+index 80370fed..616c831d 100644
 --- a/src/layerPart.cpp
 +++ b/src/layerPart.cpp
 @@ -49,7 +49,7 @@ void createLayerParts(SliceMeshStorage& mesh, Slicer* slicer)
@@ -12,19 +12,19 @@ index 80370fe..07d40f2 100644
      {
          SliceLayer& layer_storage = mesh.layers[layer_nr];
 diff --git a/src/support.cpp b/src/support.cpp
-index a1081ad..1638c95 100644
+index dc39a8fe..13c69862 100644
 --- a/src/support.cpp
 +++ b/src/support.cpp
-@@ -854,7 +854,7 @@ void AreaSupport::generateSupportAreasForMesh(SliceDataStorage& storage, const S
-     const double tan_angle = tan(angle) - 0.01;  // the XY-component of the supportAngle
-     xy_disallowed_per_layer[0] = storage.getLayerOutlines(0, false).offset(xy_distance);
+@@ -860,7 +860,7 @@ void AreaSupport::generateSupportAreasForMesh(SliceDataStorage& storage, const S
+     constexpr bool no_prime_tower = false;
+     xy_disallowed_per_layer[0] = storage.getLayerOutlines(0, no_support, no_prime_tower).offset(xy_distance);
      // for all other layers (of non support meshes) compute the overhang area and possibly use that when calculating the support disallowed area
 -    #pragma omp parallel for default(none) shared(xy_disallowed_per_layer, storage, mesh) schedule(dynamic)
 +    #pragma omp parallel for default(none) shared(xy_disallowed_per_layer, storage, mesh, layer_count, is_support_mesh_place_holder, use_xy_distance_overhang, z_distance_top, tan_angle, xy_distance, xy_distance_overhang) schedule(dynamic)
-     for (unsigned int layer_idx = 1; layer_idx < layer_count; layer_idx++)
+     for (size_t layer_idx = 1; layer_idx < layer_count; layer_idx++)
      {
-         Polygons outlines = storage.getLayerOutlines(layer_idx, false);
-@@ -1054,7 +1054,7 @@ void AreaSupport::generateSupportAreasForMesh(SliceDataStorage& storage, const S
+         Polygons outlines = storage.getLayerOutlines(layer_idx, no_support, no_prime_tower);
+@@ -1056,7 +1056,7 @@ void AreaSupport::generateSupportAreasForMesh(SliceDataStorage& storage, const S
          const int max_checking_layer_idx = std::min(static_cast<int>(storage.support.supportLayers.size())
                                                    , static_cast<int>(layer_count - (layer_z_distance_top - 1)));
          const size_t max_checking_idx_size_t = std::max(0, max_checking_layer_idx);
@@ -32,4 +32,5 @@ index a1081ad..1638c95 100644
 +#pragma omp parallel for default(none) shared(support_areas, storage, max_checking_idx_size_t, layer_z_distance_top) schedule(dynamic)
          for (size_t layer_idx = 0; layer_idx < max_checking_idx_size_t; layer_idx++)
          {
-             support_areas[layer_idx] = support_areas[layer_idx].difference(storage.getLayerOutlines(layer_idx + layer_z_distance_top - 1, false));
+             constexpr bool no_support = false;
+
diff --git a/CuraEngine.spec b/CuraEngine.spec
index f26e140..c766746 100644
--- a/CuraEngine.spec
+++ b/CuraEngine.spec
@@ -1,7 +1,7 @@
 Name:           CuraEngine
 Epoch:          1
-Version:        3.6.0
-Release:        4%{?dist}
+Version:        4.0.0
+Release:        1%{?dist}
 Summary:        Engine for processing 3D models into G-code instructions for 3D printers
 License:        AGPLv3+
 URL:            https://github.com/Ultimaker/%{name}
@@ -64,6 +64,9 @@ make install DESTDIR=%{buildroot}
 %{_bindir}/%{name}
 
 %changelog
+* Wed Apr 03 2019 Gabriel Féron <feron.gabriel@gmail.com> - 4.0.0-1
+- Update to 4.0.0
+
 * Thu Jan 31 2019 Fedora Release Engineering <releng@fedoraproject.org> - 1:3.6.0-4
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_30_Mass_Rebuild
 
diff --git a/sources b/sources
index 3470a0f..0b79428 100644
--- a/sources
+++ b/sources
@@ -1,2 +1,2 @@
-SHA512 (CuraEngine-3.6.0.tar.gz) = 340dad4c697fb0d7b633091715a904ae7df8973626e217ae2528d0121723c07a6cf0bbc740b9ad9980f3b288fa690c9c3ee43d90914264855dace007bbb334c8
+SHA512 (CuraEngine-4.0.0.tar.gz) = 478dc2554abea24baeec18e2b2d65a790dd6d31a3b11c87d839a9e928679f40bab9703e86e473bba36f72355485d66bf63515692ac75bceae5881e6537f48c46
 SHA512 (e6afb9cbae4064da8c3e69af3ff5c4629579c1d2.tar.gz) = 232ef301d4d6c82c7c5f0e4234b9160cc815f3b6bcc35d341cdf8738646f2f0887ee9838680699f4c9f4274b1390036b2c4fb3ebc2d663af8ff888114dc9f04b