diff --git a/src/nodebuild.cpp b/src/nodebuild.cpp
index 6b17c9629d..30c44b69c0 100644
--- a/src/nodebuild.cpp
+++ b/src/nodebuild.cpp
@@ -818,41 +818,57 @@ void FNodeBuilder::SplitSegs (DWORD set, node_t &node, DWORD splitseg, DWORD &ou
 			newvert.y += fixed_t(frac * double(Vertices[seg->v2].y - newvert.y));
 			vertnum = VertexMap->SelectVertexClose (newvert);
 
-			if (vertnum == (unsigned int)seg->v1 || vertnum == (unsigned int)seg->v2)
+			if (vertnum != (unsigned int)seg->v1 && vertnum != (unsigned int)seg->v2)
 			{
-				Printf("SelectVertexClose selected endpoint of seg %u\n", set);
+				seg2 = SplitSeg(set, vertnum, sidev[0]);
+
+				Segs[seg2].next = outset0;
+				outset0 = seg2;
+				Segs[set].next = outset1;
+				outset1 = set;
+				_count0++;
+				_count1++;
+
+				// Also split the seg on the back side
+				if (Segs[set].partner != DWORD_MAX)
+				{
+					int partner1 = Segs[set].partner;
+					int partner2 = SplitSeg(partner1, vertnum, sidev[1]);
+					// The newly created seg stays in the same set as the
+					// back seg because it has not been considered for splitting
+					// yet. If it had been, then the front seg would have already
+					// been split, and we would not be in this default case.
+					// Moreover, the back seg may not even be in the set being
+					// split, so we must not move its pieces into the out sets.
+					Segs[partner1].next = partner2;
+					Segs[partner2].partner = seg2;
+					Segs[seg2].partner = partner2;
+				}
+
+				if (GLNodes)
+				{
+					AddIntersection(node, vertnum);
+				}
 			}
-
-			seg2 = SplitSeg (set, vertnum, sidev[0]);
-
-			Segs[seg2].next = outset0;
-			outset0 = seg2;
-			Segs[set].next = outset1;
-			outset1 = set;
-			_count0++;
-			_count1++;
-
-			// Also split the seg on the back side
-			if (Segs[set].partner != DWORD_MAX)
+			else
 			{
-				int partner1 = Segs[set].partner;
-				int partner2 = SplitSeg (partner1, vertnum, sidev[1]);
-				// The newly created seg stays in the same set as the
-				// back seg because it has not been considered for splitting
-				// yet. If it had been, then the front seg would have already
-				// been split, and we would not be in this default case.
-				// Moreover, the back seg may not even be in the set being
-				// split, so we must not move its pieces into the out sets.
-				Segs[partner1].next = partner2;
-				Segs[partner2].partner = seg2;
-				Segs[seg2].partner = partner2;
+				// all that matters here is to prevent a crash so we must make sure that we do not end up with all segs being sorted to the same side - even if this may not be correct.
+				// But if we do not do that this code would not be able to move on. Just discarding the seg is also not an option because it won't guarantee that we achieve an actual split.
+				if (_count0 == 0)
+				{
+					side = 0;
+					seg->next = outset0;
+					outset0 = set;
+					_count0++;
+				}
+				else
+				{
+					side = 1;
+					seg->next = outset1;
+					outset1 = set;
+					_count1++;
+				}
 			}
-
-			if (GLNodes)
-			{
-				AddIntersection (node, vertnum);
-			}
-
 			break;
 		}
 		if (side >= 0 && GLNodes)