diff --git a/hybsys.c b/hybsys.c
index 216a99ca..21108461 100644
--- a/hybsys.c
+++ b/hybsys.c
@@ -391,6 +391,7 @@ hybsys_compute_press_flux(int nc, const int *pconn, const int *conn,
 }
 
 
+#if 0
 /*
  * Routines to assemble global matrix
  *
@@ -585,3 +586,4 @@ hybsys_assemble(int nc, int nf,
    hybsys_build_matrix_structure(nc, nf, pconn, conn, &A->ia, &A->ja);
    hybsys_assemble_global_system(nc, nf, pconn, conn, S, R, &A->sa, b, A->ia);
 }
+#endif
diff --git a/hybsys.h b/hybsys.h
index c71d2fd1..c3ea31fc 100644
--- a/hybsys.h
+++ b/hybsys.h
@@ -5,10 +5,6 @@
 #ifndef HYBSYS_H_INCLUDED
 #define HYBSYS_H_INCLUDED
 
-#ifndef MAT_SIZE_T
-#define MAT_SIZE_T int
-#endif
-
 struct hybsys {
     double *L;                  /* C2' * inv(B) * C1 - P */
     double *F1;                 /* C1' * inv(B)          */
@@ -19,18 +15,6 @@ struct hybsys {
 };
 
 
-
-struct Sparse
-{
-    int        m;
-    int        n;
-    MAT_SIZE_T *ia;
-    MAT_SIZE_T *ja;
-    double     *sa;
-};
-
-
-
 struct hybsys *
 hybsys_allocate_symm(int max_nconn, int nc, int nconn_tot);
 
@@ -98,10 +82,4 @@ hybsys_compute_press_flux(int nc, const int *pconn, const int *conn,
                           const double *pi, double *press, double *flux,
                           double *work);
 
-void
-hybsys_assemble(int nc, int nf,
-                const int *pconn, const int *conn,
-                const double *S, const double *R,
-                struct Sparse *A, double **b);
-
 #endif  /* HYBSYS_H_INCLUDED */