diff --git a/casadm/extended_err_msg.c b/casadm/extended_err_msg.c
index 6b4b842..dd8b1c9 100644
--- a/casadm/extended_err_msg.c
+++ b/casadm/extended_err_msg.c
@@ -256,7 +256,11 @@ struct {
 		KCAS_ERR_CACHE_STOPPING,
 		"Cache being stopped"
 	},
+	{
 
+		KCAS_ERR_CORE_IN_ACTIVE_STATE,
+		"Core device is in active state"
+	},
 
 };
 
diff --git a/modules/cas_cache/utils/cas_err.h b/modules/cas_cache/utils/cas_err.h
index fd4badc..c0443ac 100644
--- a/modules/cas_cache/utils/cas_err.h
+++ b/modules/cas_cache/utils/cas_err.h
@@ -65,6 +65,7 @@ struct {
 	{ KCAS_ERR_A_PART,			EINVAL	},
 	{ KCAS_ERR_REMOVED_DIRTY,		EIO	},
 	{ KCAS_ERR_STOPPED_DIRTY,		EIO	},
+	{ KCAS_ERR_CORE_IN_ACTIVE_STATE,	ENODEV	},
 };
 
 /*******************************************/
diff --git a/modules/include/cas_ioctl_codes.h b/modules/include/cas_ioctl_codes.h
index ff5c582..4b98ceb 100644
--- a/modules/include/cas_ioctl_codes.h
+++ b/modules/include/cas_ioctl_codes.h
@@ -589,6 +589,9 @@ enum kcas_error {
 
 	/** Cache already being stopped*/
 	KCAS_ERR_CACHE_STOPPING,
+
+	/** Core device is in active state */
+	KCAS_ERR_CORE_IN_ACTIVE_STATE
 };
 
 #endif