diff --git a/renderer.h b/renderer.h
index 3489949..884ca87 100644
--- a/renderer.h
+++ b/renderer.h
@@ -663,8 +663,9 @@ uint8_t _LCR_rendererCheckMapTriCover(const S3L_Index *t1, const S3L_Index *t2)
 
             points2D[12] = LCR_renderer.mapVerts[3 * t3[freeVert] + coordX];
             points2D[13] = LCR_renderer.mapVerts[3 * t3[freeVert] + coordY];
-           
-            if (_LCR_rendererQuadCoversTri(points2D + 6,points2D))
+
+            if (_LCR_rendererQuadLooksConvex(points2D +6) &&
+              _LCR_rendererQuadCoversTri(points2D + 6,points2D))
             {
               result |= 1 << j;
               break;