diff --git a/Sources/Mesh+STL.swift b/Sources/Mesh+STL.swift
index d68c9d9f..3efc290d 100644
--- a/Sources/Mesh+STL.swift
+++ b/Sources/Mesh+STL.swift
@@ -25,7 +25,7 @@ private extension Polygon {
         facet normal \(plane.normal.stlString)
         \touter loop
         \(vertices.map {
-            "\t\t\($0.position.stlString)"
+            "\t\tvertex \($0.position.stlString)"
         }.joined(separator: "\n"))
         \tendloop
         endfacet
diff --git a/Tests/MeshTests.swift b/Tests/MeshTests.swift
index d09dea9b..63b9ae88 100644
--- a/Tests/MeshTests.swift
+++ b/Tests/MeshTests.swift
@@ -338,86 +338,86 @@ class MeshTests: XCTestCase {
         solid Foo
         facet normal 1 0 0
         \touter loop
-        \t\t1 0 1
-        \t\t1 0 0
-        \t\t1 1 0
+        \t\tvertex 1 0 1
+        \t\tvertex 1 0 0
+        \t\tvertex 1 1 0
         \tendloop
         endfacet
         facet normal 1 0 0
         \touter loop
-        \t\t1 0 1
-        \t\t1 1 0
-        \t\t1 1 1
+        \t\tvertex 1 0 1
+        \t\tvertex 1 1 0
+        \t\tvertex 1 1 1
         \tendloop
         endfacet
         facet normal -1 0 0
         \touter loop
-        \t\t0 0 0
-        \t\t0 0 1
-        \t\t0 1 1
+        \t\tvertex 0 0 0
+        \t\tvertex 0 0 1
+        \t\tvertex 0 1 1
         \tendloop
         endfacet
         facet normal -1 0 0
         \touter loop
-        \t\t0 0 0
-        \t\t0 1 1
-        \t\t0 1 0
+        \t\tvertex 0 0 0
+        \t\tvertex 0 1 1
+        \t\tvertex 0 1 0
         \tendloop
         endfacet
         facet normal 0 1 0
         \touter loop
-        \t\t0 1 1
-        \t\t1 1 1
-        \t\t1 1 0
+        \t\tvertex 0 1 1
+        \t\tvertex 1 1 1
+        \t\tvertex 1 1 0
         \tendloop
         endfacet
         facet normal 0 1 0
         \touter loop
-        \t\t0 1 1
-        \t\t1 1 0
-        \t\t0 1 0
+        \t\tvertex 0 1 1
+        \t\tvertex 1 1 0
+        \t\tvertex 0 1 0
         \tendloop
         endfacet
         facet normal 0 -1 0
         \touter loop
-        \t\t0 0 0
-        \t\t1 0 0
-        \t\t1 0 1
+        \t\tvertex 0 0 0
+        \t\tvertex 1 0 0
+        \t\tvertex 1 0 1
         \tendloop
         endfacet
         facet normal 0 -1 0
         \touter loop
-        \t\t0 0 0
-        \t\t1 0 1
-        \t\t0 0 1
+        \t\tvertex 0 0 0
+        \t\tvertex 1 0 1
+        \t\tvertex 0 0 1
         \tendloop
         endfacet
         facet normal 0 0 1
         \touter loop
-        \t\t0 0 1
-        \t\t1 0 1
-        \t\t1 1 1
+        \t\tvertex 0 0 1
+        \t\tvertex 1 0 1
+        \t\tvertex 1 1 1
         \tendloop
         endfacet
         facet normal 0 0 1
         \touter loop
-        \t\t0 0 1
-        \t\t1 1 1
-        \t\t0 1 1
+        \t\tvertex 0 0 1
+        \t\tvertex 1 1 1
+        \t\tvertex 0 1 1
         \tendloop
         endfacet
         facet normal 0 0 -1
         \touter loop
-        \t\t1 0 0
-        \t\t0 0 0
-        \t\t0 1 0
+        \t\tvertex 1 0 0
+        \t\tvertex 0 0 0
+        \t\tvertex 0 1 0
         \tendloop
         endfacet
         facet normal 0 0 -1
         \touter loop
-        \t\t1 0 0
-        \t\t0 1 0
-        \t\t1 1 0
+        \t\tvertex 1 0 0
+        \t\tvertex 0 1 0
+        \t\tvertex 1 1 0
         \tendloop
         endfacet
         endsolid Foo