2 files changed, 4 insertions, 4 deletions

diff --git a/csv.c b/csv.c
index 020a221..58b1861 100644
--- a/csv.c
+++ b/csv.c
@@ -235,7 +235,7 @@ csv_cleanup(csv_t *csv)
 }
 
 int
-csv_nfields(csv_t *csv)
+csv_nfields(const csv_t * const csv)
 {
         assert(csv != NULL);
 
@@ -246,7 +246,7 @@ csv_nfields(csv_t *csv)
 }
 
 const char *
-csv_field(csv_t *csv, int idx)
+csv_field(const csv_t * const csv, int idx)
 {
         assert(csv != NULL);
         assert(idx >= 0 && idx < csv->csv_field.pos);
diff --git a/csv.h b/csv.h
index 690df89..c7aaffc 100644
--- a/csv.h
+++ b/csv.h
@@ -58,8 +58,8 @@ void csv_cleanup(csv_t *csv);
 int csv_read(csv_t *csv, FILE *in);
 
 /* field access */
-int csv_nfields(csv_t *csv);
-const char * csv_field(csv_t *csv, int idx);
+int csv_nfields(const csv_t * const csv);
+const char * csv_field(const csv_t * const csv, int idx);
 
 /* write */
 void csv_write(FILE *out, const csv_t * const csv);