diff --git a/src/raft.cpp b/src/raft.cpp
index 28241c988f..8229892713 100644
--- a/src/raft.cpp
+++ b/src/raft.cpp
@@ -1,4 +1,6 @@
 /** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
+#include <clipper/clipper.hpp>
+
 #include "raft.h"
 #include "support.h"
 
@@ -8,15 +10,15 @@ void generateRaft(SliceDataStorage& storage, int distance)
 {
     if (storage.draft_protection_shield.size() > 0)
     {
-        storage.raftOutline = storage.raftOutline.unionPolygons(storage.draft_protection_shield.offset(distance));
+        storage.raftOutline = storage.raftOutline.unionPolygons(storage.draft_protection_shield.offset(distance, ClipperLib::jtRound));
     }
     else if (storage.oozeShield.size() > 0 && storage.oozeShield[0].size() > 0)
     {
-        storage.raftOutline = storage.raftOutline.unionPolygons(storage.oozeShield[0].offset(distance));
+        storage.raftOutline = storage.raftOutline.unionPolygons(storage.oozeShield[0].offset(distance, ClipperLib::jtRound));
     }
     else 
     {
-        storage.raftOutline = storage.getLayerOutlines(0, true).offset(distance);
+        storage.raftOutline = storage.getLayerOutlines(0, true).offset(distance, ClipperLib::jtRound);
     }
 }