diff --git a/lib/cacheOptimization.js b/lib/cacheOptimization.js
index 943d1e6a..5dbea7f0 100644
--- a/lib/cacheOptimization.js
+++ b/lib/cacheOptimization.js
@@ -74,10 +74,11 @@ function cacheOptimization(gltf, cacheSize) {
             var primitivesLength = primitives.length;
             for (var i = 0; i < primitivesLength; i++) {
                 primitive = primitives[i];
-                geometry = gltfPrimitiveToCesiumGeometry(gltf, primitive);
-                GeometryPipeline.reorderForPostVertexCache(geometry, cacheSize);
-
-                cesiumGeometryToGltfPrimitive(gltf, primitive, geometry);
+                if (defined(primitive.indices)) {
+                    geometry = gltfPrimitiveToCesiumGeometry(gltf, primitive);
+                    GeometryPipeline.reorderForPostVertexCache(geometry, cacheSize);
+                    cesiumGeometryToGltfPrimitive(gltf, primitive, geometry);
+                }
             }
         }
     }
diff --git a/specs/lib/cacheOptimizationSpec.js b/specs/lib/cacheOptimizationSpec.js
index d944638f..6110fbea 100644
--- a/specs/lib/cacheOptimizationSpec.js
+++ b/specs/lib/cacheOptimizationSpec.js
@@ -1,4 +1,7 @@
 'use strict';
+var Cesium = require('cesium');
+var GeometryPipeline = Cesium.GeometryPipeline;
+
 var addDefaults = require('../../lib/addDefaults');
 var cacheOptimization = require('../../lib/cacheOptimization');
 var readAccessor = require('../../lib/readAccessor');
@@ -59,4 +62,24 @@ describe('cacheOptimization', function() {
                 expect(positions).toEqual(unpackedOptimizedVertices);
             }), done).toResolve();
     });
+
+    it('doesn\'t run if a primitive has no indices', function() {
+        var gltf = {
+            meshes : {
+                mesh : {
+                    primitives : [
+                        {
+                            attributes : {
+                                POSITION : 'notImportant',
+                                NORMAL : 'notImportantEither'
+                            }
+                        }
+                    ]
+                }
+            }
+        };
+        spyOn(GeometryPipeline, 'reorderForPostVertexCache');
+        cacheOptimization(gltf);
+        expect(GeometryPipeline.reorderForPostVertexCache).not.toHaveBeenCalled();
+    });
 });