diff --git a/res/res_pjsip.c b/res/res_pjsip.c
index d2ce7f285d..33bf32080f 100644
--- a/res/res_pjsip.c
+++ b/res/res_pjsip.c
@@ -971,6 +971,8 @@
Maximum number of threads in the res_pjsip threadpool.
A value of 0 indicates no maximum.
+
+ Must be of type 'system'.
Options that apply globally to all SIP communications
@@ -984,6 +986,8 @@
Value used in User-Agent header for SIP requests and Server header for SIP responses.
+
+ Must be of type 'global'.