diff --git a/doc/snippets/Tridiagonalization_decomposeInPlace.cpp b/doc/snippets/Tridiagonalization_decomposeInPlace.cpp
index 93dcfca..3cdce67 100644
--- a/doc/snippets/Tridiagonalization_decomposeInPlace.cpp
+++ b/doc/snippets/Tridiagonalization_decomposeInPlace.cpp
@@ -4,7 +4,8 @@
 
 VectorXd diag(5);
 VectorXd subdiag(4);
-internal::tridiagonalization_inplace(A, diag, subdiag, true);
+VectorXd hcoeffs(4);  // Scratch space for householder reflector.
+internal::tridiagonalization_inplace(A, diag, subdiag, hcoeffs, true);
 cout << "The orthogonal matrix Q is:" << endl << A << endl;
 cout << "The diagonal of the tridiagonal matrix T is:" << endl << diag << endl;
 cout << "The subdiagonal of the tridiagonal matrix T is:" << endl << subdiag << endl;