diff --git a/test/runtests.jl b/test/runtests.jl
index 69c255e..8a2372f 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -36,6 +36,7 @@ include("test_sh_intersection.jl")
 include("test_isinside.jl")
 include("test_jctweld.jl")
 include("test_isinclosure.jl")
+include("test_permute_vertices.jl")
 
 include("test_trgauss.jl")
 include("test_chartquad.jl")
diff --git a/test/test_permute_vertices.jl b/test/test_permute_vertices.jl
new file mode 100644
index 0000000..a095eff
--- /dev/null
+++ b/test/test_permute_vertices.jl
@@ -0,0 +1,34 @@
+using CompScienceMeshes
+using Test
+
+splx = simplex(
+    point(0,0,0),
+    point(1,0,0),
+    point(0,1,0)
+);
+
+@test normal(splx) ≈ point(0,0,1)
+
+splx1 = CompScienceMeshes.permute_vertices(splx, [2,1,3])
+@test normal(splx1) ≈ point(0,0,1)
+
+splx2 = CompScienceMeshes.flip_normal(splx)
+@test normal(splx2) ≈ point(0,0,-1)
+
+for i in 1:2
+    @test CompScienceMeshes.tangents(splx2,i) ≈ CompScienceMeshes.tangents(splx,i)
+end
+
+splx3 = simplex(
+    point(1,0.5,0),
+    point(-1,0.5,0),
+    point(-1,2.5,0)
+)
+
+isct = CompScienceMeshes.intersection2(splx, splx3)
+@test length(isct) == 1
+
+splx4, splx5 = isct[1]
+@test volume(splx4) ≈ volume(splx5)
+@test normal(splx4) ≈ -normal(splx5)
+