diff --git a/libsmartcols/src/libsmartcols.h.in b/libsmartcols/src/libsmartcols.h.in
index b946d5b16..de2f271cf 100644
--- a/libsmartcols/src/libsmartcols.h.in
+++ b/libsmartcols/src/libsmartcols.h.in
@@ -257,7 +257,7 @@ enum {
 extern int scols_table_set_termforce(struct libscols_table *tb, int force);
 extern int scols_table_get_termforce(const struct libscols_table *tb);
 extern int scols_table_set_termwidth(struct libscols_table *tb, size_t width);
-extern size_t scols_table_get_termwidth(struct libscols_table *tb);
+extern size_t scols_table_get_termwidth(const struct libscols_table *tb);
 
 
 /* table_print.c */
diff --git a/libsmartcols/src/table.c b/libsmartcols/src/table.c
index eb0998077..fcb53b64a 100644
--- a/libsmartcols/src/table.c
+++ b/libsmartcols/src/table.c
@@ -1148,7 +1148,7 @@ int scols_table_set_termwidth(struct libscols_table *tb, size_t width)
  *
  * Returns: terminal width or a negative value in case of an error.
  */
-size_t scols_table_get_termwidth(struct libscols_table *tb)
+size_t scols_table_get_termwidth(const struct libscols_table *tb)
 {
 	return tb->termwidth;
 }