diff --git a/makefile b/makefile
index f155f5c..cc8b326 100644
--- a/makefile
+++ b/makefile
@@ -43,12 +43,6 @@ register:; $(Q)./bin/authc user register $(NAME) $(EMAIL)
 validate:; $(Q)./bin/authc user validate $(NAME) $(ACTIVATION_KEY)
 get-user:; $(Q)./bin/authc user get $(NAME) $(LOGIN_OPT)
 
-USER_DB ?= /tmp/migration-authd-user-db.txt
-$(USER_DB): ; ./bin/migration-filter.awk < /tmp/usrdb | grep -a -v "^INVALID" | sort | uniq > $(USER_DB)
-migration-file: $(USER_DB)
-migrate-user:;      ./bin/authc user migrate $(NAME) $(PASSWORD_HASH) $(LOGIN_OPT)
-migrate-all-users:; ./bin/authc migration-script $(USER_DB) $(LOGIN_OPT)
-
 SERVICE    ?= 'auth'
 RESOURCE   ?= '*'
 UID        ?= 1000
@@ -89,3 +83,5 @@ wipe-db:
 
 release:
 	make build-server OPTS="--progress --release"
+
+-include migration.mk
diff --git a/migration.mk b/migration.mk
new file mode 100644
index 0000000..40463cd
--- /dev/null
+++ b/migration.mk
@@ -0,0 +1,30 @@
+# This is the migration makefile.
+#
+# WHAT IS NEEDED FOR THE MIGRATION:
+#
+# - $(SQLDB): a dump of the SQL database (format: login password domain)
+#
+# HOW MIGRATION WORKS, STEP BY STEP (`migration` rule):
+#
+# 1. migration-file    -> create the $(USER_DB) file
+# 2. migrate-all-users -> migrate all user accounts
+#
+# AFTER THE `migration` RULE: go to the dnsmanagerd repository and follow instructions.
+
+# DB from SQL, format: login password domain
+SQLDB ?= /tmp/usrdb
+
+USER_DB ?= /tmp/migration-authd-user-db.txt
+
+$(USER_DB):
+	./bin/migration-filter.awk < $(SQLDB) | grep -a -v "^INVALID" | sort | uniq > $(USER_DB)
+
+migration-file: $(USER_DB)
+
+migrate-user:
+	./bin/authc user migrate $(NAME) $(PASSWORD_HASH) $(LOGIN_OPT)
+
+migrate-all-users:
+	./bin/authc migration-script $(USER_DB) $(LOGIN_OPT)
+
+migration: migration-file migrate-all-users