diff --git a/configs/samples/prometheus.conf.sample b/configs/samples/prometheus.conf.sample
index 3ee9290db9acf5f5910255b0e2e302dc22123d7b..ee4a1965eef8dfaa5c5e37a4a80e425a4c43bffa 100644
--- a/configs/samples/prometheus.conf.sample
+++ b/configs/samples/prometheus.conf.sample
@@ -10,6 +10,10 @@
 ; Because Prometheus scrapes statistics from HTTP servers, this module requires
 ; Asterisk's built-in HTTP server to be enabled and configured properly.
 ;
+; Module Dependencies:
+; only if Asterisk is build with pjproject bundled (default)
+; * res_pjsip.so
+; * res_pjsip_outbound_registration.so
 
 ; Settings that affect all statistic generation
 [general]
diff --git a/res/res_prometheus.c b/res/res_prometheus.c
index 11b8f0279edaaa75a12d2e83685d5dbbc5d6f183..4aacf6e85ce4b637fab77419a35993bfb6d1c938 100644
--- a/res/res_prometheus.c
+++ b/res/res_prometheus.c
@@ -27,6 +27,7 @@
 /*** MODULEINFO
 	<use>pjproject</use>
 	<use type="module">res_pjsip</use>
+	<use type="module">res_pjsip_outbound_registration</use>
 	<support_level>extended</support_level>
  ***/
 
@@ -1002,6 +1003,7 @@ AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_GLOBAL_SYMBOLS | AST_MODFLAG_LOAD_
 	.reload = reload_module,
 	.load_pri = AST_MODPRI_DEFAULT,
 #ifdef HAVE_PJPROJECT
-	.requires = "res_pjsip",
+	/* This module explicitly calls into res_pjsip if Asterisk is built with PJSIP support, so they are required. */
+	.requires = "res_pjsip,res_pjsip_outbound_registration",
 #endif
 );