diff --git a/src/qmckl_context.org b/src/qmckl_context.org
index 1aba050..5d1f510 100644
--- a/src/qmckl_context.org
+++ b/src/qmckl_context.org
@@ -1,6 +1,6 @@
 # -*- mode: org -*-
 
-#+TITLE: Context 
+#+TITLE: Context
 
 This file is written in C because it is more natural to express the context in
 C than in Fortran.
@@ -17,7 +17,7 @@ C than in Fortran.
   is stored in the following data structure, which can't be seen
   outside of the library.
 
-  
+
   #+BEGIN_SRC C :tangle qmckl_context.h
 #define QMCKL_DEFAULT_PRECISION 53
 #define QMCKL_DEFAULT_RANGE     2
@@ -66,11 +66,11 @@ qmckl_context qmckl_context_create() {
 ** =qmckl_context_copy=
 
    #+BEGIN_SRC C :tangle qmckl_context.h
-qmckl_context qmckl_context_copy(qmckl_context context);
+qmckl_context qmckl_context_copy(const qmckl_context context);
    #+END_SRC
 
    #+BEGIN_SRC C :tangle qmckl_context.c
-qmckl_context qmckl_context_copy(qmckl_context context) {
+qmckl_context qmckl_context_copy(const qmckl_context context) {
 
   qmckl_context_struct* old_context;
   qmckl_context_struct* new_context;
@@ -102,11 +102,11 @@ qmckl_context qmckl_context_copy(qmckl_context context) {
 ** =qmckl_context_set_precision=
 
    #+BEGIN_SRC C :tangle qmckl_context.h
-qmckl_context qmckl_context_set_precision(qmckl_context context, int precision);
+qmckl_context qmckl_context_set_precision(const qmckl_context context, int precision);
    #+END_SRC
 
    #+BEGIN_SRC C :tangle qmckl_context.c
-qmckl_context qmckl_context_set_precision(qmckl_context context, int precision) {
+qmckl_context qmckl_context_set_precision(const qmckl_context context, int precision) {
   qmckl_context_struct* ctx;
 
   if (precision <  2) return (qmckl_context) 0;
@@ -120,11 +120,11 @@ qmckl_context qmckl_context_set_precision(qmckl_context context, int precision)
 
 ** =qmckl_context_set_range=
    #+BEGIN_SRC C :tangle qmckl_context.h
-qmckl_context qmckl_context_set_range(qmckl_context context, int range);
+qmckl_context qmckl_context_set_range(const qmckl_context context, int range);
    #+END_SRC
 
    #+BEGIN_SRC C :tangle qmckl_context.c
-qmckl_context qmckl_context_set_range(qmckl_context context, int range) {
+qmckl_context qmckl_context_set_range(const qmckl_context context, int range) {
   qmckl_context_struct* ctx;
 
   if (range <  2) return (qmckl_context) 0;
@@ -141,11 +141,11 @@ qmckl_context qmckl_context_set_range(qmckl_context context, int range) {
 ** =qmckl_context_get_precision=
 
    #+BEGIN_SRC C :tangle qmckl_context.h
-int qmckl_context_get_precision(qmckl_context context);
+int qmckl_context_get_precision(const qmckl_context context);
    #+END_SRC
 
    #+BEGIN_SRC C :tangle qmckl_context.c
-int qmckl_context_get_precision(qmckl_context context) {
+int qmckl_context_get_precision(const qmckl_context context) {
   qmckl_context_struct* ctx;
   ctx = (qmckl_context_struct*) context;
   return ctx->precision;
@@ -155,11 +155,11 @@ int qmckl_context_get_precision(qmckl_context context) {
 ** =qmckl_context_get_range=
 
    #+BEGIN_SRC C :tangle qmckl_context.h
-int qmckl_context_get_range(qmckl_context context);
+int qmckl_context_get_range(const qmckl_context context);
    #+END_SRC
 
    #+BEGIN_SRC C :tangle qmckl_context.c
-int qmckl_context_get_range(qmckl_context context) {
+int qmckl_context_get_range(const qmckl_context context) {
   qmckl_context_struct* ctx;
   ctx = (qmckl_context_struct*) context;
   return ctx->range;