diff --git a/Eigen/src/Core/CommaInitializer.h b/Eigen/src/Core/CommaInitializer.h
index 5c89d14e4..7c2eea8a6 100644
--- a/Eigen/src/Core/CommaInitializer.h
+++ b/Eigen/src/Core/CommaInitializer.h
@@ -47,7 +47,7 @@ struct CommaInitializer
   {
     eigen_assert(m_xpr.rows() >= other.rows() && m_xpr.cols() >= other.cols()
       && "Cannot comma-initialize a 0x0 matrix (operator<<)");
-    m_xpr.block(0, 0, other.rows(), other.cols()) = other;
+    m_xpr.template block<OtherDerived::RowsAtCompileTime, OtherDerived::ColsAtCompileTime>(0, 0, other.rows(), other.cols()) = other;
   }
 
   /* Copy/Move constructor which transfers ownership. This is crucial in