diff --git a/src/lib-sieve/plugins/vnd.dovecot/environment/ext-vnd-environment.c b/src/lib-sieve/plugins/vnd.dovecot/environment/ext-vnd-environment.c
index b0f9246df7e3e9ed27a8c9bcc75d0d71d8c14c75..5cf5d657a21a515c33dfb25cfe1a71768dafd1b8 100644
--- a/src/lib-sieve/plugins/vnd.dovecot/environment/ext-vnd-environment.c
+++ b/src/lib-sieve/plugins/vnd.dovecot/environment/ext-vnd-environment.c
@@ -5,7 +5,8 @@
  * ---------------------------------
  *
  * Authors: Stephan Bosch
- * Specification: vendor-defined
+ * Specification: vendor-defined;
+ *   spec-bosch-sieve-dovecot-environment
  * Implementation: preliminary
  * Status: experimental
  *