diff --git a/src/plugins_exts.h b/src/plugins_exts.h
index 56ec4f3..29e1b6b 100644
--- a/src/plugins_exts.h
+++ b/src/plugins_exts.h
@@ -63,25 +63,6 @@
 void lysc_extension_instance_substatements_free(struct ly_ctx *ctx, struct lysc_ext_substmt *substmts);
 
 /**
- * @brief Get pointer to the storage of the specified substatement in the given extension instance.
- *
- * The function simplifies access into the ::lysc_ext_instance.substmts sized array.
- *
- * @param[in] ext Compiled extension instance to process.
- * @param[in] substmt Extension substatement to search for.
- * @param[out] instance_p Pointer where the storage of the @p substmt will be provided. The specific type returned depends
- * on the @p substmt and can be found in the documentation of each ::ly_stmt value. Also note that some of the substatements
- * (::lysc_node based or flags) can share the storage with other substatements. In case the pointer is NULL, still the return
- * code can be used to at least know if the substatement is allowed for the extension.
- * @param[out] cardinality_p Pointer to provide allowed cardinality of the substatements in the extension. Note that in some
- * cases, the type of the storage depends also on the cardinality of the substatement.
- * @return LY_SUCCESS if the @p substmt found.
- * @return LY_ENOT in case the @p ext is not able to store (does not allow) the specified @p substmt.
- */
-LY_ERR lysc_ext_substmt(const struct lysc_ext_instance *ext, enum ly_stmt substmt,
-        void **instance_p, enum ly_stmt_cardinality *cardinality_p);
-
-/**
  * @brief Callback to compile extension from the lysp_ext_instance to the lysc_ext_instance. The later structure is generally prepared
  * and only the extension specific data are supposed to be added (if any).
  *
diff --git a/src/schema_compile.c b/src/schema_compile.c
index 3588a7d..d725efb 100644
--- a/src/schema_compile.c
+++ b/src/schema_compile.c
@@ -143,7 +143,7 @@
     return orig;
 }
 
-LY_ERR
+API LY_ERR
 lysc_ext_substmt(const struct lysc_ext_instance *ext, enum ly_stmt substmt, void **instance_p, enum ly_stmt_cardinality *cardinality_p)
 {
     LY_ARRAY_COUNT_TYPE u;
diff --git a/src/tree_schema.h b/src/tree_schema.h
index b6c5246..2670781 100644
--- a/src/tree_schema.h
+++ b/src/tree_schema.h
@@ -2159,6 +2159,25 @@
 struct lysp_feature *lysp_feature_next(const struct lysp_feature *last, const struct lysp_module *pmod, uint32_t *idx);
 
 /**
+ * @brief Get pointer to the storage of the specified substatement in the given extension instance.
+ *
+ * The function simplifies access into the ::lysc_ext_instance.substmts sized array.
+ *
+ * @param[in] ext Compiled extension instance to process.
+ * @param[in] substmt Extension substatement to search for.
+ * @param[out] instance_p Pointer where the storage of the @p substmt will be provided. The specific type returned depends
+ * on the @p substmt and can be found in the documentation of each ::ly_stmt value. Also note that some of the substatements
+ * (::lysc_node based or flags) can share the storage with other substatements. In case the pointer is NULL, still the return
+ * code can be used to at least know if the substatement is allowed for the extension.
+ * @param[out] cardinality_p Pointer to provide allowed cardinality of the substatements in the extension. Note that in some
+ * cases, the type of the storage depends also on the cardinality of the substatement.
+ * @return LY_SUCCESS if the @p substmt found.
+ * @return LY_ENOT in case the @p ext is not able to store (does not allow) the specified @p substmt.
+ */
+LY_ERR lysc_ext_substmt(const struct lysc_ext_instance *ext, enum ly_stmt substmt,
+        void **instance_p, enum ly_stmt_cardinality *cardinality_p);
+
+/**
  * @defgroup findxpathoptions Atomize XPath options
  * Options to modify behavior of ::lys_find_xpath() and ::lys_find_xpath_atoms() searching for schema nodes in schema tree.
  * @{