1 files changed, 7 insertions, 1 deletions
diff --git a/libcrystfel/src/crystal.c b/libcrystfel/src/crystal.c
index 1cfaf621..3ea148bd 100644
--- a/libcrystfel/src/crystal.c
+++ b/libcrystfel/src/crystal.c
@@ -123,7 +123,7 @@ Crystal *crystal_new()
  * Returns: a (shallow) copy of @cryst, or NULL on failure.
  *
  */
-Crystal *crystal_copy(Crystal *cryst)
+Crystal *crystal_copy(const Crystal *cryst)
 {
 	Crystal *c;
 
@@ -160,6 +160,12 @@ UnitCell *crystal_get_cell(Crystal *cryst)
 }
 
 
+const UnitCell *crystal_get_cell_const(const Crystal *cryst)
+{
+	return cryst->cell;
+}
+
+
 double crystal_get_profile_radius(Crystal *cryst)
 {
 	return cryst->profile_radius;