4 files changed, 12 insertions, 12 deletions
diff --git a/libcrystfel/src/cell-utils.c b/libcrystfel/src/cell-utils.c
index d269e703..d5662971 100644
--- a/libcrystfel/src/cell-utils.c
+++ b/libcrystfel/src/cell-utils.c
@@ -868,7 +868,7 @@ static int get_angle_rad(char **bits, int nbits, double *pl)
  * Writes \p cell to \p fh, in CrystFEL unit cell file format
  *
  */
-void write_cell(UnitCell *cell, FILE *fh)
+void write_cell(const UnitCell *cell, FILE *fh)
 {
 	double a, b, c, al, be, ga;
 	LatticeType lt;
diff --git a/libcrystfel/src/cell-utils.h b/libcrystfel/src/cell-utils.h
index 1c356588..05618385 100644
--- a/libcrystfel/src/cell-utils.h
+++ b/libcrystfel/src/cell-utils.h
@@ -61,7 +61,7 @@ extern void cell_print_full(UnitCell *cell);
 
 extern UnitCell *load_cell_from_pdb(const char *filename);
 extern UnitCell *load_cell_from_file(const char *filename);
-extern void write_cell(UnitCell *cell, FILE *fh);
+extern void write_cell(const UnitCell *cell, FILE *fh);
 
 extern int cell_is_sensible(UnitCell *cell);
 
diff --git a/libcrystfel/src/cell.c b/libcrystfel/src/cell.c
index f6ed412d..23a5e46b 100644
--- a/libcrystfel/src/cell.c
+++ b/libcrystfel/src/cell.c
@@ -157,7 +157,7 @@ void cell_free(UnitCell *cell)
  * \returns True if cell has its parameters specified.
  *
  */
-int cell_has_parameters(UnitCell *cell)
+int cell_has_parameters(const UnitCell *cell)
 {
 	if ( cell == NULL ) return 0;
 	return cell->have_parameters;
@@ -567,19 +567,19 @@ int cell_get_reciprocal(const UnitCell *cell,
 }
 
 
-char cell_get_centering(UnitCell *cell)
+char cell_get_centering(const UnitCell *cell)
 {
 	return cell->centering;
 }
 
 
-LatticeType cell_get_lattice_type(UnitCell *cell)
+LatticeType cell_get_lattice_type(const UnitCell *cell)
 {
 	return cell->lattice_type;
 }
 
 
-struct g6 cell_get_G6(UnitCell *cell)
+struct g6 cell_get_G6(const UnitCell *cell)
 {
 	double a, b, c, al, be, ga;
 	struct g6 g;
@@ -594,7 +594,7 @@ struct g6 cell_get_G6(UnitCell *cell)
 }
 
 
-char cell_get_unique_axis(UnitCell *cell)
+char cell_get_unique_axis(const UnitCell *cell)
 {
 	return cell->unique_axis;
 }
diff --git a/libcrystfel/src/cell.h b/libcrystfel/src/cell.h
index 3deb92ff..d201d059 100644
--- a/libcrystfel/src/cell.h
+++ b/libcrystfel/src/cell.h
@@ -101,7 +101,7 @@ extern UnitCell *cell_new_from_reciprocal_axes(struct rvec as, struct rvec bs,
 extern UnitCell *cell_new_from_direct_axes(struct rvec as, struct rvec bs,
                                            struct rvec cs);
 
-extern int cell_has_parameters(UnitCell *cell);
+extern int cell_has_parameters(const UnitCell *cell);
 
 extern void cell_set_cartesian(UnitCell *cell,
                                double ax, double ay, double az,
@@ -129,7 +129,7 @@ extern void cell_set_reciprocal(UnitCell *cell,
                                 double bsx, double bsy, double bsz,
                                 double csx, double csy, double csz);
 
-extern LatticeType cell_get_lattice_type(UnitCell *cell);
+extern LatticeType cell_get_lattice_type(const UnitCell *cell);
 extern void cell_set_lattice_type(UnitCell *cell, LatticeType lattice_type);
 
 struct g6
@@ -142,12 +142,12 @@ struct g6
 	double F;
 };
 
-extern struct g6 cell_get_G6(UnitCell *cell);
+extern struct g6 cell_get_G6(const UnitCell *cell);
 
-extern char cell_get_centering(UnitCell *cell);
+extern char cell_get_centering(const UnitCell *cell);
 extern void cell_set_centering(UnitCell *cell, char centering);
 
-extern char cell_get_unique_axis(UnitCell *cell);
+extern char cell_get_unique_axis(const UnitCell *cell);
 extern void cell_set_unique_axis(UnitCell *cell, char unique_axis);
 
 extern const char *cell_rep(UnitCell *cell);