diff --git a/Eigen/src/Core/ProductBase.h b/Eigen/src/Core/ProductBase.h
index 3bd3487d6..233ed6467 100644
--- a/Eigen/src/Core/ProductBase.h
+++ b/Eigen/src/Core/ProductBase.h
@@ -256,16 +256,16 @@ class ScaledProduct
     : Base(prod.lhs(),prod.rhs()), m_prod(prod), m_alpha(x) {}
 
     template<typename Dest>
-    inline void evalTo(Dest& dst) const { dst.setZero(); scaleAndAddTo(dst,m_alpha); }
+    inline void evalTo(Dest& dst) const { dst.setZero(); scaleAndAddTo(dst, Scalar(1)); }
 
     template<typename Dest>
-    inline void addTo(Dest& dst) const { scaleAndAddTo(dst,m_alpha); }
+    inline void addTo(Dest& dst) const { scaleAndAddTo(dst, Scalar(1)); }
 
     template<typename Dest>
-    inline void subTo(Dest& dst) const { scaleAndAddTo(dst,-m_alpha); }
+    inline void subTo(Dest& dst) const { scaleAndAddTo(dst, Scalar(-1)); }
 
     template<typename Dest>
-    inline void scaleAndAddTo(Dest& dst,Scalar alpha) const { m_prod.derived().scaleAndAddTo(dst,alpha); }
+    inline void scaleAndAddTo(Dest& dst,Scalar alpha) const { m_prod.derived().scaleAndAddTo(dst,alpha * m_alpha); }
 
     const Scalar& alpha() const { return m_alpha; }
     
diff --git a/test/product_extra.cpp b/test/product_extra.cpp
index 25a9974b9..ca302b469 100644
--- a/test/product_extra.cpp
+++ b/test/product_extra.cpp
@@ -116,6 +116,16 @@ template<typename MatrixType> void product_extra(const MatrixType& m)
   VERIFY_IS_APPROX(tmp, m1 * m1.adjoint() * s1);
 }
 
+// Regression test for bug reported at http://forum.kde.org/viewtopic.php?f=74&t=96947
+void mat_mat_scalar_scalar_product()
+{
+  Eigen::Matrix2Xd dNdxy(2, 3);
+  dNdxy << -0.5, 0.5, 0,
+           -0.3, 0, 0.3;
+  double det = 6.0, wt = 0.5;
+  VERIFY_IS_APPROX(dNdxy.transpose()*dNdxy*det*wt, det*wt*dNdxy.transpose()*dNdxy);
+}
+  
 void zero_sized_objects()
 {
   // Bug 127
@@ -145,6 +155,7 @@ void test_product_extra()
   for(int i = 0; i < g_repeat; i++) {
     CALL_SUBTEST_1( product_extra(MatrixXf(internal::random<int>(1,EIGEN_TEST_MAX_SIZE), internal::random<int>(1,EIGEN_TEST_MAX_SIZE))) );
     CALL_SUBTEST_2( product_extra(MatrixXd(internal::random<int>(1,EIGEN_TEST_MAX_SIZE), internal::random<int>(1,EIGEN_TEST_MAX_SIZE))) );
+    CALL_SUBTEST_2( mat_mat_scalar_scalar_product() );
     CALL_SUBTEST_3( product_extra(MatrixXcf(internal::random<int>(1,EIGEN_TEST_MAX_SIZE/2), internal::random<int>(1,EIGEN_TEST_MAX_SIZE/2))) );
     CALL_SUBTEST_4( product_extra(MatrixXcd(internal::random<int>(1,EIGEN_TEST_MAX_SIZE/2), internal::random<int>(1,EIGEN_TEST_MAX_SIZE/2))) );
     CALL_SUBTEST_5( zero_sized_objects() );