diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0e1c2e807..54297b52e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -33,6 +33,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Check and create default permissions individually [#671](https://github.com/greenbone/gvmd/pull/671)
 - Add -f arg to sendmail call in email alert [#676](https://github.com/greenbone/gvmd/pull/676) [#678](https://github.com/greenbone/gvmd/pull/678)
 - Change get_tickets to use the status text for filtering. [#697](https://github.com/greenbone/gvmd/pull/697)
+- Made checks to prevent duplicate user names stricter. [#708](https://github.com/greenbone/gvmd/pull/708)
 
 ### Fixed
 - A PostgreSQL statement order issue [#611](https://github.com/greenbone/gvmd/issues/611) has been addressed [#642](https://github.com/greenbone/gvmd/pull/642)
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 74edf966f..831e4a0e6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -113,7 +113,7 @@ include (CPack)
 
 ## Variables
 
-set (GVMD_DATABASE_VERSION 217)
+set (GVMD_DATABASE_VERSION 218)
 
 set (GVMD_SCAP_DATABASE_VERSION 15)
 
diff --git a/src/manage_migrators.c b/src/manage_migrators.c
index 1ee595fe0..69e7d2c35 100644
--- a/src/manage_migrators.c
+++ b/src/manage_migrators.c
@@ -1284,6 +1284,39 @@ migrate_216_to_217 ()
   return 0;
 }
 
+/**
+ * @brief Migrate the database from version 217 to version 218.
+ *
+ * @return 0 success, -1 error.
+ */
+int
+migrate_217_to_218 ()
+{
+  sql_begin_immediate ();
+
+  /* Ensure that the database is currently version 217. */
+
+  if (manage_db_version () != 217)
+    {
+      sql_rollback ();
+      return -1;
+    }
+
+  /* Update the database. */
+
+  /* Add an UNIQUE constraint to the name column of users */
+
+  sql ("ALTER TABLE users ADD UNIQUE (name);");
+
+  /* Set the database version to 218. */
+
+  set_db_version (218);
+
+  sql_commit ();
+
+  return 0;
+}
+
 #undef UPDATE_DASHBOARD_SETTINGS
 
 /**
@@ -1307,6 +1340,7 @@ static migrator_t database_migrators[] = {
   {215, migrate_214_to_215},
   {216, migrate_215_to_216},
   {217, migrate_216_to_217},
+  {218, migrate_217_to_218},
   /* End marker. */
   {-1, NULL}};
 
diff --git a/src/manage_pg.c b/src/manage_pg.c
index 3bef36a63..0294cc5f8 100644
--- a/src/manage_pg.c
+++ b/src/manage_pg.c
@@ -2058,7 +2058,7 @@ create_tables ()
        " (id SERIAL PRIMARY KEY,"
        "  uuid text UNIQUE NOT NULL,"
        "  owner integer REFERENCES users (id) ON DELETE RESTRICT,"
-       "  name text NOT NULL,"
+       "  name text UNIQUE NOT NULL,"
        "  comment text,"
        "  password text,"
        "  timezone text,"