diff --git a/src/lib/yang/adaptor_config.cc b/src/lib/yang/adaptor_config.cc
index 86e2248b81..a97bf09edb 100644
--- a/src/lib/yang/adaptor_config.cc
+++ b/src/lib/yang/adaptor_config.cc
@@ -6,6 +6,7 @@
 
 #include <config.h>
 
+#include <dhcpsrv/subnet_id.h>
 #include <yang/adaptor_config.h>
 
 using namespace std;
diff --git a/src/lib/yang/adaptor_config.h b/src/lib/yang/adaptor_config.h
index 77ede57640..930e4245df 100644
--- a/src/lib/yang/adaptor_config.h
+++ b/src/lib/yang/adaptor_config.h
@@ -7,6 +7,7 @@
 #ifndef ISC_ADAPTOR_CONFIG_H
 #define ISC_ADAPTOR_CONFIG_H 1
 
+#include <dhcpsrv/subnet_id.h>
 #include <yang/adaptor_host.h>
 #include <yang/adaptor_option.h>
 #include <yang/adaptor_pool.h>
@@ -60,7 +61,7 @@ protected:
     /// @param set The reference to the set of assigned IDs.
     /// @return True if all subnets have an ID, false otherwise.
     static bool subnetsCollectID(isc::data::ConstElementPtr subnets,
-                                 SubnetIDSet& set);
+                                 isc::dhcp::SubnetIDSet& set);
 
     /// @brief Collects subnet-ids in all subnets in all shared network list.
     ///
@@ -74,7 +75,7 @@ protected:
     /// @param subsel The subnet list name.
     /// @return True if all subnets have an ID, false otherwise.
     static bool sharedNetworksCollectID(isc::data::ConstElementPtr networks,
-                                        SubnetIDSet& set,
+                                        isc::dhcp::SubnetIDSet& set,
                                         const std::string& subsel);
 
     /// @brief Assigns subnet-id to every subnet in a subnet list.
@@ -86,7 +87,8 @@ protected:
     /// @param set The reference to the set of assigned IDs.
     /// @param next The next ID.
     static void subnetsAssignID(isc::data::ConstElementPtr subnets,
-                                SubnetIDSet& set, isc::dhcp::SubnetID& next);
+                                isc::dhcp::SubnetIDSet& set,
+                                isc::dhcp::SubnetID& next);
 
     /// @brief Assigns subnet-id to every subnet in a shared network list.
     ///
@@ -98,7 +100,7 @@ protected:
     /// @param next The next ID.
     /// @param subsel The subnet list name.
     static void sharedNetworksAssignID(isc::data::ConstElementPtr networks,
-                                       SubnetIDSet& set,
+                                       isc::dhcp::SubnetIDSet& set,
                                        isc::dhcp::SubnetID& next,
                                        const std::string& subsel);
 
diff --git a/src/lib/yang/adaptor_subnet.cc b/src/lib/yang/adaptor_subnet.cc
index c22af2d050..0beba823e3 100644
--- a/src/lib/yang/adaptor_subnet.cc
+++ b/src/lib/yang/adaptor_subnet.cc
@@ -6,6 +6,7 @@
 
 #include <config.h>
 
+#include <dhcpsrv/subnet_id.h>
 #include <yang/adaptor_subnet.h>
 
 using namespace std;
diff --git a/src/lib/yang/adaptor_subnet.h b/src/lib/yang/adaptor_subnet.h
index 214708e541..f357eb9c70 100644
--- a/src/lib/yang/adaptor_subnet.h
+++ b/src/lib/yang/adaptor_subnet.h
@@ -10,14 +10,9 @@
 #include <dhcpsrv/subnet_id.h>
 #include <yang/adaptor.h>
 
-#include <unordered_set>
-
 namespace isc {
 namespace yang {
 
-/// @brief Set of SubnetIDs.
-using SubnetIDSet = std::unordered_set<isc::dhcp::SubnetID>;
-
 /// @brief JSON adaptor for subnets adding IDs and canonizes relays.
 ///
 /// Adding IDs is done in two passes walking through subnets.
@@ -38,14 +33,16 @@ public:
     /// @param subnet The subnet.
     /// @param set The reference to the set of assigned IDs.
     /// @return True if the subnet has an ID, false otherwise.
-    static bool collectID(isc::data::ConstElementPtr subnet, SubnetIDSet& set);
+    static bool collectID(isc::data::ConstElementPtr subnet,
+                          isc::dhcp::SubnetIDSet& set);
 
     /// @brief Assign subnet ID.
     ///
     /// @param subnet The subnet.
     /// @param set The reference to the set of assigned IDs.
     /// @param next The next ID.
-    static void assignID(isc::data::ElementPtr subnet, SubnetIDSet& set,
+    static void assignID(isc::data::ElementPtr subnet,
+                         isc::dhcp::SubnetIDSet& set,
                          isc::dhcp::SubnetID& next);
 
     /// @brief Update relay.
diff --git a/src/lib/yang/tests/adaptor_subnet_unittests.cc b/src/lib/yang/tests/adaptor_subnet_unittests.cc
index 85aac8a4a7..4b744b4877 100644
--- a/src/lib/yang/tests/adaptor_subnet_unittests.cc
+++ b/src/lib/yang/tests/adaptor_subnet_unittests.cc
@@ -8,6 +8,7 @@
 
 #include <gtest/gtest.h>
 
+#include <dhcpsrv/subnet_id.h>
 #include <testutils/gtest_utils.h>
 #include <yang/adaptor_subnet.h>