diff --git a/include/ceres/solver.h b/include/ceres/solver.h
index 791630d..b2fa3ae 100644
--- a/include/ceres/solver.h
+++ b/include/ceres/solver.h
@@ -104,7 +104,8 @@
 
       // Choose a default sparse linear algebra library in the order:
       //
-      //   SUITE_SPARSE > CX_SPARSE > EIGEN_SPARSE
+      //   SUITE_SPARSE > CX_SPARSE > EIGEN_SPARSE > NO_SPARSE
+      sparse_linear_algebra_library_type = NO_SPARSE;
 #if !defined(CERES_NO_SUITESPARSE)
       sparse_linear_algebra_library_type = SUITE_SPARSE;
 #else
diff --git a/include/ceres/types.h b/include/ceres/types.h
index a07c893..8915188 100644
--- a/include/ceres/types.h
+++ b/include/ceres/types.h
@@ -157,7 +157,12 @@
 
   // Eigen's sparse linear algebra routines. In particular Ceres uses
   // the Simplicial LDLT routines.
-  EIGEN_SPARSE
+  EIGEN_SPARSE,
+
+  // No sparse linear solver should be used.  This does not necessarily
+  // imply that Ceres was built without any sparse library, although that
+  // is the likely use case, merely that one should not be used.
+  NO_SPARSE
 };
 
 enum DenseLinearAlgebraLibraryType {