diff --git a/src/libslic3r/TreeSupport.cpp b/src/libslic3r/TreeSupport.cpp
index b0faa19dd..cbb779be0 100644
--- a/src/libslic3r/TreeSupport.cpp
+++ b/src/libslic3r/TreeSupport.cpp
@@ -923,7 +923,9 @@ static void generate_initial_areas(
     // does not turn valid in double the amount of layers a slope of support angle would take to travel xy_distance, nothing reasonable will come from it. 
     // The 2*z_distance_delta is only a catch for when the support angle is very high.
     // Used only if not min_xy_dist.
-    const coord_t max_overhang_insert_lag = std::max<coord_t>(round_up_divide(mesh_config.xy_distance, max_overhang_speed / 2), 2 * mesh_config.z_distance_top_layers);
+    const coord_t max_overhang_insert_lag = mesh_config.z_distance_top_layers > 0 ?
+        std::max<coord_t>(round_up_divide(mesh_config.xy_distance, max_overhang_speed / 2), 2 * mesh_config.z_distance_top_layers) :
+        0;
 
     //FIXME 
     size_t num_support_layers = print_object.layer_count();