diff --git a/dlls/d3dx8/tests/math.c b/dlls/d3dx8/tests/math.c
index d0d0b0390aa..a5980209346 100644
--- a/dlls/d3dx8/tests/math.c
+++ b/dlls/d3dx8/tests/math.c
@@ -41,6 +41,15 @@ static void D3X8QuaternionTest(void)
     expected=0.0f;
     got = D3DXQuaternionLength(NULL);
     ok(fabs( got - expected ) < admitted_error, "Expected: %f, Got: %f\n", expected, got);
+
+/*_______________D3DXQuaternionLengthSq________________________*/
+    expected = 121.0f;
+    got = D3DXQuaternionLengthSq(&q);
+    ok(fabs( got - expected ) < admitted_error, "Expected: %f, Got: %f\n", expected, got);
+    /* Tests the case NULL */
+    expected=0.0f;
+    got = D3DXQuaternionLengthSq(NULL);
+    ok(fabs( got - expected ) < admitted_error, "Expected: %f, Got: %f\n", expected, got);
 }
 
 static void D3X8Vector2Test(void)
@@ -172,6 +181,15 @@ static void D3X8Vector3Test(void)
     expected=0.0f;
     got = D3DXVec3Length(NULL);
     ok(fabs( got - expected ) < admitted_error, "Expected: %f, Got: %f\n", expected, got);
+
+/*_______________D3DXVec3LengthSq________________________*/
+    expected = 121.0f;
+    got = D3DXVec3LengthSq(&u);
+    ok(fabs( got - expected ) < admitted_error, "Expected: %f, Got: %f\n", expected, got);
+   /* Tests the case NULL */
+    expected=0.0f;
+    got = D3DXVec3LengthSq(NULL);
+    ok(fabs( got - expected ) < admitted_error, "Expected: %f, Got: %f\n", expected, got);
 }
 
 static void D3X8Vector4Test(void)
@@ -189,6 +207,15 @@ static void D3X8Vector4Test(void)
     expected=0.0f;
     got = D3DXVec4Length(NULL);
     ok(fabs( got - expected ) < admitted_error, "Expected: %f, Got: %f\n", expected, got);
+
+/*_______________D3DXVec4LengthSq________________________*/
+    expected = 121.0f;
+    got = D3DXVec4LengthSq(&u);
+    ok(fabs( got - expected ) < admitted_error, "Expected: %f, Got: %f\n", expected, got);
+    /* Tests the case NULL */
+    expected=0.0f;
+    got = D3DXVec4LengthSq(NULL);
+    ok(fabs( got - expected ) < admitted_error, "Expected: %f, Got: %f\n", expected, got);
 }
 
 START_TEST(math)
diff --git a/include/d3dx8math.inl b/include/d3dx8math.inl
index 94e0019c885..c8de09bb23c 100644
--- a/include/d3dx8math.inl
+++ b/include/d3dx8math.inl
@@ -101,6 +101,12 @@ static inline FLOAT D3DXVec3Length(CONST D3DXVECTOR3 *pv)
     return sqrt( (pv->x) * (pv->x) + (pv->y) * (pv->y) + (pv->z) * (pv->z) );
 }
 
+static inline FLOAT D3DXVec3LengthSq(CONST D3DXVECTOR3 *pv)
+{
+    if (!pv) return 0.0f;
+    return (pv->x) * (pv->x) + (pv->y) * (pv->y) + (pv->z) * (pv->z);
+}
+
 /*__________________D3DXVECTOR4_______________________*/
 
 static inline FLOAT D3DXVec4Length(CONST D3DXVECTOR4 *pv)
@@ -109,6 +115,11 @@ static inline FLOAT D3DXVec4Length(CONST D3DXVECTOR4 *pv)
     return sqrt( (pv->x) * (pv->x) + (pv->y) * (pv->y) + (pv->z) * (pv->z) + (pv->w) * (pv->w) );
 }
 
+static inline FLOAT D3DXVec4LengthSq(CONST D3DXVECTOR4 *pv)
+{
+    if (!pv) return 0.0f;
+    return (pv->x) * (pv->x) + (pv->y) * (pv->y) + (pv->z) * (pv->z) + (pv->w) * (pv->w);
+}
 
 /*__________________D3DXQUATERNION____________________*/
 
@@ -118,7 +129,10 @@ static inline FLOAT D3DXQuaternionLength( CONST D3DXQUATERNION *pq)
     return sqrt( (pq->x) * (pq->x) + (pq->y) * (pq->y) + (pq->z) * (pq->z) + (pq->w) * (pq->w) );
 }
 
-
-
+static inline FLOAT D3DXQuaternionLengthSq( CONST D3DXQUATERNION *pq)
+{
+    if (!pq) return 0.0f;
+    return (pq->x) * (pq->x) + (pq->y) * (pq->y) + (pq->z) * (pq->z) + (pq->w) * (pq->w);
+}
 
 #endif