diff --git a/src/libslic3r/ExtrusionEntity.cpp b/src/libslic3r/ExtrusionEntity.cpp
index d5d09a3e9..39e3f63ab 100644
--- a/src/libslic3r/ExtrusionEntity.cpp
+++ b/src/libslic3r/ExtrusionEntity.cpp
@@ -68,7 +68,8 @@ void ExtrusionPath::polygons_covered_by_spacing(Polygons &out, const float scale
 {
     // Instantiating the Flow class to get the line spacing.
     // Don't know the nozzle diameter, setting to zero. It shall not matter it shall be optimized out by the compiler.
-    Flow flow(this->width, this->height, 0.f, is_bridge(this->role()));
+    // if the spacing is negative, use the width instead. can happen on ironing second pass.
+    Flow flow(this->width, this->height, 0.f, (this->width*4 < this->height)?true:is_bridge(this->role()));
     polygons_append(out, offset(this->polyline, 0.5f * double(flow.scaled_spacing()) + scaled_epsilon));
 }
 
diff --git a/src/libslic3r/Fill/FillSmooth.cpp b/src/libslic3r/Fill/FillSmooth.cpp
index b8abadf71..7c21fc5b7 100644
--- a/src/libslic3r/Fill/FillSmooth.cpp
+++ b/src/libslic3r/Fill/FillSmooth.cpp
@@ -132,7 +132,8 @@ namespace Slic3r {
 
         // first infill
         FillParams first_pass_params = params;
-        first_pass_params.role = ExtrusionRole::erSolidInfill;
+        if(first_pass_params.role != ExtrusionRole::erSupportMaterial && first_pass_params.role != ExtrusionRole::erSupportMaterialInterface)
+            first_pass_params.role = ExtrusionRole::erSolidInfill;
         perform_single_fill(0, *eecroot, *surface, first_pass_params, volumeToOccupy);
 
         //use monotonic for ironing pass