diff --git a/source/model/modelutils.js b/source/model/modelutils.js
index de3b5af..9d63b84 100644
--- a/source/model/modelutils.js
+++ b/source/model/modelutils.js
@@ -259,12 +259,35 @@ OV.GetModelTopology = function (model)
 
 OV.IsModelSolid = function (model)
 {
+    function GetEdgeOrientationInTriangle (topology, triangleIndex, edgeIndex)
+    {
+        const triangle = topology.triangles[triangleIndex];
+        const triEdge1 = topology.triangleEdges[triangle.triEdge1];
+        const triEdge2 = topology.triangleEdges[triangle.triEdge2];
+        const triEdge3 = topology.triangleEdges[triangle.triEdge3];
+        if (triEdge1.edge === edgeIndex) {
+            return triEdge1.reversed;
+        }
+        if (triEdge2.edge === edgeIndex) {
+            return triEdge2.reversed;
+        }
+        if (triEdge3.edge === edgeIndex) {
+            return triEdge3.reversed;
+        }
+        return null;
+    }
+
     const topology = OV.GetModelTopology (model);
-    for (let i = 0; i < topology.edges.length; i++) {
-        const edge = topology.edges[i];
+    for (let edgeIndex = 0; edgeIndex < topology.edges.length; edgeIndex++) {
+        const edge = topology.edges[edgeIndex];
         if (edge.triangles.length !== 2) {
             return false;
         }
+        const edgeOrientation1 = GetEdgeOrientationInTriangle (topology, edge.triangles[0], edgeIndex);
+        const edgeOrientation2 = GetEdgeOrientationInTriangle (topology, edge.triangles[1], edgeIndex);
+        if (edgeOrientation1 === edgeOrientation2) {
+            return false;
+        }
     }
     return true;
 };
diff --git a/test/tests/quantities_test.js b/test/tests/quantities_test.js
index 537bf81..bfb976b 100644
--- a/test/tests/quantities_test.js
+++ b/test/tests/quantities_test.js
@@ -14,6 +14,33 @@ describe ('Quantities', function () {
         assert.strictEqual (volume, null);
     });
 
+    it ('Cube with Wrongly Oriented Triangle Volume Calculation', function () {
+        var cube = new OV.Mesh ();
+        cube.AddVertex (new OV.Coord3D (0.0, 0.0, 0.0));
+        cube.AddVertex (new OV.Coord3D (1.0, 0.0, 0.0));
+        cube.AddVertex (new OV.Coord3D (1.0, 1.0, 0.0));
+        cube.AddVertex (new OV.Coord3D (0.0, 1.0, 0.0));
+        cube.AddVertex (new OV.Coord3D (0.0, 0.0, 1.0));
+        cube.AddVertex (new OV.Coord3D (1.0, 0.0, 1.0));
+        cube.AddVertex (new OV.Coord3D (1.0, 1.0, 1.0));
+        cube.AddVertex (new OV.Coord3D (0.0, 1.0, 1.0));
+        cube.AddTriangle (new OV.Triangle (0, 1, 5));
+        cube.AddTriangle (new OV.Triangle (0, 5, 4));
+        cube.AddTriangle (new OV.Triangle (1, 2, 6));
+        cube.AddTriangle (new OV.Triangle (1, 6, 5));
+        cube.AddTriangle (new OV.Triangle (2, 3, 7));
+        cube.AddTriangle (new OV.Triangle (2, 7, 6));
+        cube.AddTriangle (new OV.Triangle (3, 0, 4));
+        cube.AddTriangle (new OV.Triangle (3, 4, 7));
+        cube.AddTriangle (new OV.Triangle (0, 3, 2));
+        cube.AddTriangle (new OV.Triangle (0, 2, 1));
+        cube.AddTriangle (new OV.Triangle (4, 5, 6));
+        cube.AddTriangle (new OV.Triangle (4, 7, 6));
+        const model = testUtils.GetModelWithOneMesh (cube);
+        const volume = OV.CalculateModelVolume (model);
+        assert.strictEqual (volume, null);
+    });
+
     it ('Cube Surface Area Calculation', function () {
         const model = testUtils.GetModelWithOneMesh (testUtils.GetCubeMesh ());
         const surface = OV.CalculateModelSurfaceArea (model);