diff --git a/docs/harfbuzz-sections.txt b/docs/harfbuzz-sections.txt
index 6f0da7218..fafc7c7fc 100644
--- a/docs/harfbuzz-sections.txt
+++ b/docs/harfbuzz-sections.txt
@@ -637,6 +637,7 @@ hb_ot_var_normalize_coords
 HB_SET_VALUE_INVALID
 hb_set_add
 hb_set_add_range
+hb_set_add_sorted_codepoints
 hb_set_allocation_successful
 hb_set_copy
 hb_set_clear
diff --git a/src/hb-set.cc b/src/hb-set.cc
index 7c80fc267..b2f9091f3 100644
--- a/src/hb-set.cc
+++ b/src/hb-set.cc
@@ -257,9 +257,14 @@ hb_set_add (hb_set_t       *set,
 }
 
 /**
- * Adds num_codepoints codepoints to a set at once.
+ * hb_set_add_sorted_array:
+ * @set: A set
+ * @sorted_codepoints: (array length=num_codepoints) Array of codepoints to add
+ * @num_codepoints: Length of @sorted_codepoints
+ *
+ * Adds @num_codepoints codepoints to a set at once.
  * The codepoints array must be in increasing order,
- * with size at least num_codepoints.
+ * with size at least @num_codepoints.
  *
  * Since: REPLACEME
  */
@@ -268,6 +273,7 @@ hb_set_add_sorted_array (hb_set_t             *set,
 		         const hb_codepoint_t *sorted_codepoints,
 		         unsigned int          num_codepoints)
 {
+  /* Immutible-safe. */
   set->add_sorted_array (sorted_codepoints,
 		         num_codepoints,
 		         sizeof(hb_codepoint_t));
diff --git a/src/hb-set.h b/src/hb-set.h
index 19374e022..adf34fb6a 100644
--- a/src/hb-set.h
+++ b/src/hb-set.h
@@ -60,11 +60,6 @@ typedef struct hb_set_t hb_set_t;
 HB_EXTERN hb_set_t *
 hb_set_create (void);
 
-HB_EXTERN void
-hb_set_add_sorted_array (hb_set_t             *set,
-		         const hb_codepoint_t *sorted_codepoints,
-		         unsigned int          num_codepoints);
-
 HB_EXTERN hb_set_t *
 hb_set_get_empty (void);
 
@@ -115,6 +110,11 @@ hb_set_add_range (hb_set_t       *set,
 		  hb_codepoint_t  first,
 		  hb_codepoint_t  last);
 
+HB_EXTERN void
+hb_set_add_sorted_array (hb_set_t             *set,
+		         const hb_codepoint_t *sorted_codepoints,
+		         unsigned int          num_codepoints);
+
 HB_EXTERN void
 hb_set_del (hb_set_t       *set,
 	    hb_codepoint_t  codepoint);