diff --git a/src/plugins_exts/structure.c b/src/plugins_exts/structure.c
index 781cde0..3580ba3 100644
--- a/src/plugins_exts/structure.c
+++ b/src/plugins_exts/structure.c
@@ -16,6 +16,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "compat.h"
 #include "libyang.h"
 #include "plugins_exts.h"
 
@@ -29,6 +30,12 @@
     struct lysc_node *child;
 };
 
+struct lysc_ext_instance_augment_structure {
+    uint16_t flags;
+    const char *dsc;
+    const char *ref;
+};
+
 /**
  * @brief Compile structure extension instances.
  *
@@ -37,11 +44,11 @@
 static LY_ERR
 structure_compile(struct lysc_ctx *cctx, const struct lysp_ext_instance *p_ext, struct lysc_ext_instance *c_ext)
 {
-    LY_ERR ret;
+    LY_ERR rc;
     LY_ARRAY_COUNT_TYPE u;
     struct lysc_module *mod_c;
     const struct lysc_node *child;
-    struct lysc_ext_instance_structure *struct_ext;
+    struct lysc_ext_instance_structure *struct_data;
     uint32_t prev_options = *lysc_ctx_get_options(cctx);
 
     /* structure can appear only at the top level of a YANG module or submodule */
@@ -72,90 +79,229 @@
     }
 
     /* allocate the storage */
-    struct_ext = calloc(1, sizeof *struct_ext);
-    if (!struct_ext) {
+    struct_data = calloc(1, sizeof *struct_data);
+    if (!struct_data) {
         goto emem;
     }
-    c_ext->data = struct_ext;
+    c_ext->data = struct_data;
 
     /* compile substatements */
-    LY_ARRAY_CREATE_GOTO(cctx->ctx, c_ext->substmts, 14, ret, emem);
+    LY_ARRAY_CREATE_GOTO(cctx->ctx, c_ext->substmts, 14, rc, emem);
     LY_ARRAY_INCREMENT(c_ext->substmts);
     c_ext->substmts[0].stmt = LY_STMT_MUST;
     c_ext->substmts[0].cardinality = LY_STMT_CARD_ANY;
-    c_ext->substmts[0].storage = &struct_ext->musts;
+    c_ext->substmts[0].storage = &struct_data->musts;
 
     LY_ARRAY_INCREMENT(c_ext->substmts);
     c_ext->substmts[1].stmt = LY_STMT_STATUS;
     c_ext->substmts[1].cardinality = LY_STMT_CARD_OPT;
-    c_ext->substmts[1].storage = &struct_ext->flags;
+    c_ext->substmts[1].storage = &struct_data->flags;
 
     LY_ARRAY_INCREMENT(c_ext->substmts);
     c_ext->substmts[2].stmt = LY_STMT_DESCRIPTION;
     c_ext->substmts[2].cardinality = LY_STMT_CARD_OPT;
-    c_ext->substmts[2].storage = &struct_ext->dsc;
+    c_ext->substmts[2].storage = &struct_data->dsc;
 
     LY_ARRAY_INCREMENT(c_ext->substmts);
     c_ext->substmts[3].stmt = LY_STMT_REFERENCE;
     c_ext->substmts[3].cardinality = LY_STMT_CARD_OPT;
-    c_ext->substmts[3].storage = &struct_ext->ref;
+    c_ext->substmts[3].storage = &struct_data->ref;
 
     LY_ARRAY_INCREMENT(c_ext->substmts);
     c_ext->substmts[4].stmt = LY_STMT_TYPEDEF;
     c_ext->substmts[4].cardinality = LY_STMT_CARD_ANY;
-    c_ext->substmts[4].storage = &struct_ext->typedefs;
+    c_ext->substmts[4].storage = &struct_data->typedefs;
 
     LY_ARRAY_INCREMENT(c_ext->substmts);
     c_ext->substmts[5].stmt = LY_STMT_GROUPING;
     c_ext->substmts[5].cardinality = LY_STMT_CARD_ANY;
-    c_ext->substmts[5].storage = &struct_ext->groupings;
+    c_ext->substmts[5].storage = &struct_data->groupings;
 
     /* data-def-stmt */
     LY_ARRAY_INCREMENT(c_ext->substmts);
     c_ext->substmts[6].stmt = LY_STMT_CONTAINER;
     c_ext->substmts[6].cardinality = LY_STMT_CARD_ANY;
-    c_ext->substmts[6].storage = &struct_ext->child;
+    c_ext->substmts[6].storage = &struct_data->child;
 
     LY_ARRAY_INCREMENT(c_ext->substmts);
     c_ext->substmts[7].stmt = LY_STMT_LEAF;
     c_ext->substmts[7].cardinality = LY_STMT_CARD_ANY;
-    c_ext->substmts[7].storage = &struct_ext->child;
+    c_ext->substmts[7].storage = &struct_data->child;
 
     LY_ARRAY_INCREMENT(c_ext->substmts);
     c_ext->substmts[8].stmt = LY_STMT_LEAF_LIST;
     c_ext->substmts[8].cardinality = LY_STMT_CARD_ANY;
-    c_ext->substmts[8].storage = &struct_ext->child;
+    c_ext->substmts[8].storage = &struct_data->child;
 
     LY_ARRAY_INCREMENT(c_ext->substmts);
     c_ext->substmts[9].stmt = LY_STMT_LIST;
     c_ext->substmts[9].cardinality = LY_STMT_CARD_ANY;
-    c_ext->substmts[9].storage = &struct_ext->child;
+    c_ext->substmts[9].storage = &struct_data->child;
 
     LY_ARRAY_INCREMENT(c_ext->substmts);
     c_ext->substmts[10].stmt = LY_STMT_CHOICE;
     c_ext->substmts[10].cardinality = LY_STMT_CARD_ANY;
-    c_ext->substmts[10].storage = &struct_ext->child;
+    c_ext->substmts[10].storage = &struct_data->child;
 
     LY_ARRAY_INCREMENT(c_ext->substmts);
     c_ext->substmts[11].stmt = LY_STMT_ANYDATA;
     c_ext->substmts[11].cardinality = LY_STMT_CARD_ANY;
-    c_ext->substmts[11].storage = &struct_ext->child;
+    c_ext->substmts[11].storage = &struct_data->child;
 
     LY_ARRAY_INCREMENT(c_ext->substmts);
     c_ext->substmts[12].stmt = LY_STMT_ANYXML;
     c_ext->substmts[12].cardinality = LY_STMT_CARD_ANY;
-    c_ext->substmts[12].storage = &struct_ext->child;
+    c_ext->substmts[12].storage = &struct_data->child;
 
     LY_ARRAY_INCREMENT(c_ext->substmts);
     c_ext->substmts[13].stmt = LY_STMT_USES;
     c_ext->substmts[13].cardinality = LY_STMT_CARD_ANY;
-    c_ext->substmts[13].storage = &struct_ext->child;
+    c_ext->substmts[13].storage = &struct_data->child;
 
     *lysc_ctx_get_options(cctx) |= LYS_COMPILE_NO_CONFIG | LYS_COMPILE_NO_DISABLED;
-    ret = lys_compile_extension_instance(cctx, p_ext, c_ext);
+    rc = lys_compile_extension_instance(cctx, p_ext, c_ext);
     *lysc_ctx_get_options(cctx) = prev_options;
-    if (ret) {
-        return ret;
+    if (rc) {
+        return rc;
+    }
+
+    return LY_SUCCESS;
+
+emem:
+    lyplg_ext_log(c_ext, LY_LLERR, LY_EMEM, lysc_ctx_get_path(cctx), "Memory allocation failed (%s()).", __func__);
+    return LY_EMEM;
+}
+
+/**
+ * @brief Compile augment-structure extension instances.
+ *
+ * Implementation of ::lyplg_ext_compile_clb callback set as lyext_plugin::compile.
+ */
+static LY_ERR
+structure_aug_compile(struct lysc_ctx *cctx, const struct lysp_ext_instance *p_ext, struct lysc_ext_instance *c_ext)
+{
+    LY_ERR rc;
+    struct lysp_stmt *stmt;
+    struct lysc_node *aug_target;
+    struct lysc_ext_instance *target_ext;
+    struct lysc_ext_instance_structure *target_data;
+    struct lysc_ext_instance_augment_structure *aug_data;
+    uint32_t prev_options = *lysc_ctx_get_options(cctx), i;
+
+    /* augment-structure can appear only at the top level of a YANG module or submodule */
+    if ((c_ext->parent_stmt != LY_STMT_MODULE) && (c_ext->parent_stmt != LY_STMT_SUBMODULE)) {
+        lyplg_ext_log(c_ext, LY_LLERR, LY_EVALID, lysc_ctx_get_path(cctx),
+                "Extension %s must not be used as a non top-level statement in \"%s\" statement.",
+                p_ext->name, ly_stmt2str(c_ext->parent_stmt));
+        return LY_EVALID;
+    }
+
+    /* augment-structure must define some data-def-stmt */
+    LY_LIST_FOR(p_ext->child, stmt) {
+        if (LY_STMT_IS_DATA_NODE(stmt->kw)) {
+            break;
+        }
+    }
+    if (!stmt) {
+        lyplg_ext_log(c_ext, LY_LLERR, LY_EVALID, lysc_ctx_get_path(cctx),
+                "Extension %s does not define any data-def-stmt statements.", p_ext->name);
+        return LY_EVALID;
+    }
+
+    /* find the target struct ext instance */
+    if ((rc = lys_compile_extension_instance_find_augment_target(cctx, p_ext->argument, &target_ext, &aug_target))) {
+        return rc;
+    }
+
+    /* check target_ext */
+    if (strcmp(target_ext->def->name, "structure") || strcmp(target_ext->def->module->name, "ietf-yang-structure-ext")) {
+        lyplg_ext_log(c_ext, LY_LLERR, LY_EVALID, lysc_ctx_get_path(cctx),
+                "Extension %s can only target extension instances of \"ietf-yang-structure-ext:structure\".", p_ext->name);
+        return LY_EVALID;
+    }
+    target_data = target_ext->data;
+
+    /* allocate the storage */
+    aug_data = calloc(1, sizeof *aug_data);
+    if (!aug_data) {
+        goto emem;
+    }
+    c_ext->data = aug_data;
+
+    /* compile substatements */
+    LY_ARRAY_CREATE_GOTO(cctx->ctx, c_ext->substmts, 12, rc, emem);
+    LY_ARRAY_INCREMENT(c_ext->substmts);
+    c_ext->substmts[0].stmt = LY_STMT_STATUS;
+    c_ext->substmts[0].cardinality = LY_STMT_CARD_OPT;
+    c_ext->substmts[0].storage = &aug_data->flags;
+
+    LY_ARRAY_INCREMENT(c_ext->substmts);
+    c_ext->substmts[1].stmt = LY_STMT_DESCRIPTION;
+    c_ext->substmts[1].cardinality = LY_STMT_CARD_OPT;
+    c_ext->substmts[1].storage = &aug_data->dsc;
+
+    LY_ARRAY_INCREMENT(c_ext->substmts);
+    c_ext->substmts[2].stmt = LY_STMT_REFERENCE;
+    c_ext->substmts[2].cardinality = LY_STMT_CARD_OPT;
+    c_ext->substmts[2].storage = &aug_data->ref;
+
+    /* data-def-stmt */
+    LY_ARRAY_INCREMENT(c_ext->substmts);
+    c_ext->substmts[3].stmt = LY_STMT_CONTAINER;
+    c_ext->substmts[3].cardinality = LY_STMT_CARD_ANY;
+    c_ext->substmts[3].storage = &target_data->child;
+
+    LY_ARRAY_INCREMENT(c_ext->substmts);
+    c_ext->substmts[4].stmt = LY_STMT_LEAF;
+    c_ext->substmts[4].cardinality = LY_STMT_CARD_ANY;
+    c_ext->substmts[4].storage = &target_data->child;
+
+    LY_ARRAY_INCREMENT(c_ext->substmts);
+    c_ext->substmts[5].stmt = LY_STMT_LEAF_LIST;
+    c_ext->substmts[5].cardinality = LY_STMT_CARD_ANY;
+    c_ext->substmts[5].storage = &target_data->child;
+
+    LY_ARRAY_INCREMENT(c_ext->substmts);
+    c_ext->substmts[6].stmt = LY_STMT_LIST;
+    c_ext->substmts[6].cardinality = LY_STMT_CARD_ANY;
+    c_ext->substmts[6].storage = &target_data->child;
+
+    LY_ARRAY_INCREMENT(c_ext->substmts);
+    c_ext->substmts[7].stmt = LY_STMT_CHOICE;
+    c_ext->substmts[7].cardinality = LY_STMT_CARD_ANY;
+    c_ext->substmts[7].storage = &target_data->child;
+
+    LY_ARRAY_INCREMENT(c_ext->substmts);
+    c_ext->substmts[8].stmt = LY_STMT_ANYDATA;
+    c_ext->substmts[8].cardinality = LY_STMT_CARD_ANY;
+    c_ext->substmts[8].storage = &target_data->child;
+
+    LY_ARRAY_INCREMENT(c_ext->substmts);
+    c_ext->substmts[9].stmt = LY_STMT_ANYXML;
+    c_ext->substmts[9].cardinality = LY_STMT_CARD_ANY;
+    c_ext->substmts[9].storage = &target_data->child;
+
+    LY_ARRAY_INCREMENT(c_ext->substmts);
+    c_ext->substmts[10].stmt = LY_STMT_USES;
+    c_ext->substmts[10].cardinality = LY_STMT_CARD_ANY;
+    c_ext->substmts[10].storage = &target_data->child;
+
+    /* case */
+    LY_ARRAY_INCREMENT(c_ext->substmts);
+    c_ext->substmts[11].stmt = LY_STMT_CASE;
+    c_ext->substmts[11].cardinality = LY_STMT_CARD_ANY;
+    c_ext->substmts[11].storage = &target_data->child;
+
+    *lysc_ctx_get_options(cctx) |= LYS_COMPILE_NO_CONFIG | LYS_COMPILE_NO_DISABLED;
+    rc = lys_compile_extension_instance_augment(cctx, p_ext, c_ext, aug_target);
+    *lysc_ctx_get_options(cctx) = prev_options;
+    if (rc) {
+        return rc;
+    }
+
+    /* data-def-statements are now part of the target extension (do not print nor free them) */
+    for (i = 0; i < 9; ++i) {
+        LY_ARRAY_DECREMENT(c_ext->substmts);
     }
 
     return LY_SUCCESS;
@@ -210,5 +356,18 @@
         .plugin.snode = NULL,
         .plugin.validate = NULL
     },
+    {
+        .module = "ietf-yang-structure-ext",
+        .revision = "2020-06-17",
+        .name = "augment-structure",
+
+        .plugin.id = "libyang 2 - structure, version 1",
+        .plugin.compile = structure_aug_compile,
+        .plugin.sprinter = structure_schema_printer,
+        .plugin.free = structure_free,
+        .plugin.node = NULL,
+        .plugin.snode = NULL,
+        .plugin.validate = NULL
+    },
     {0}     /* terminating zeroed record */
 };