types CHANGE extend functions' usability with declaring parameter const
diff --git a/src/tree_schema_internal.h b/src/tree_schema_internal.h
index e226a99..8804f1b 100644
--- a/src/tree_schema_internal.h
+++ b/src/tree_schema_internal.h
@@ -836,6 +836,6 @@
  * @return NULL otherwise.
  */
 const struct lys_module *ly_resolve_prefix(const struct ly_ctx *ctx, const char *prefix, size_t prefix_len,
-        LY_PREFIX_FORMAT format, void *prefix_data);
+        LY_PREFIX_FORMAT format, const void *prefix_data);
 
 #endif /* LY_TREE_SCHEMA_INTERNAL_H_ */