diff --git a/package/cla-sysrepo/czechlight-install-yang.sh b/package/cla-sysrepo/czechlight-install-yang.sh
index 6585b54..38e4c95 100755
--- a/package/cla-sysrepo/czechlight-install-yang.sh
+++ b/package/cla-sysrepo/czechlight-install-yang.sh
@@ -43,10 +43,24 @@
         ;;
 esac
 
-if [[ ${IETF_HW_STATE} == 1 && ! -f ${REPO}/ietf-hardware-state@2018-03-13.yang ]]; then
-    sysrepoctl --search-dirs ${YANG_DIR} --install ${YANG_DIR}/iana-hardware@2018-03-13.yang
-    sysrepoctl --search-dirs ${YANG_DIR} --install ${YANG_DIR}/ietf-hardware-state@2018-03-13.yang
-    sysrepoctl --change ietf-hardware-state --permissions 0664 --enable-feature hardware-sensor --apply
+# asks ietf-yang-library model in sysrepo for the state of a module given by $1
+# can return "implement", "import" or "" if the module is not present in the tree
+yang-module-state() {
+    sysrepocfg -f xml -X --xpath "/ietf-yang-library:modules-state/module[name='$1']/conformance-type" -d operational  | sed -n 's/\s*<conformance-type>\(.*\)<\/conformance-type>/\1/p'
+}
+
+if [[ ${IETF_HW_STATE} == 1 ]]; then
+    # if old model is implemented, remove it first. This uninstall dependent ietf-hardware if imported and not implemented
+    if [[ "$(yang-module-state ietf-hardware-state)" == "implement" ]]; then
+        sysrepoctl -u ietf-hardware-state --apply
+    fi
+
+    # if new model is not implemented
+    if [[ "$(yang-module-state ietf-hardware)" != "implement" ]]; then
+        sysrepoctl --search-dirs ${YANG_DIR} --install ${YANG_DIR}/iana-hardware@2018-03-13.yang
+        sysrepoctl --search-dirs ${YANG_DIR} --install ${YANG_DIR}/ietf-hardware@2018-03-13.yang
+        sysrepoctl --change ietf-hardware --permissions 0664 --enable-feature hardware-sensor --apply
+    fi
 fi
 
 if [[ ${YANG_ROADM} == 1 && ! -f ${REPO}/czechlight-roadm-device@2019-09-30.yang ]]; then
diff --git a/submodules/cla-sysrepo b/submodules/cla-sysrepo
index 8b06ca1..de2efcb 160000
--- a/submodules/cla-sysrepo
+++ b/submodules/cla-sysrepo
@@ -1 +1 @@
-Subproject commit 8b06ca1a975be2d9b5fa3894c18d37c9f0a2f116
+Subproject commit de2efcbe6fb676d15134215f28b71d5959f9e43b
diff --git a/submodules/velia b/submodules/velia
index 4b98876..83b62e1 160000
--- a/submodules/velia
+++ b/submodules/velia
@@ -1 +1 @@
-Subproject commit 4b98876ad3da3d45af204a4d0bca06c59d8231b2
+Subproject commit 83b62e1db6c5f6be7e008c6019b651b3124c1989