diff --git a/configs/samples/pjsip.conf.sample b/configs/samples/pjsip.conf.sample
index a6bc2fa30e85e9c3c31dd92e77bacd8cd165dc83..b3dd86a99c7c97328b9bdb7db695f60e4c95f9d4 100644
--- a/configs/samples/pjsip.conf.sample
+++ b/configs/samples/pjsip.conf.sample
@@ -837,10 +837,12 @@
                                 ; should be disposed of (default: "60")
 ;threadpool_max_size=0  ; Maximum number of threads in the res_pjsip threadpool
                         ; A value of 0 indicates no maximum (default: "0")
-;disable_tcp_switch=no  ; Disable automatic switching from UDP to TCP transports
+;disable_tcp_switch=yes ; Disable automatic switching from UDP to TCP transports
                         ; if outgoing request is too large.
                         ; See RFC 3261 section 18.1.1.
-                        ; (default: "no")
+						; Disabling this option has been known to cause interoperability
+						; issues, so disable at your own risk.
+                        ; (default: "yes")
 ;type=  ; Must be of type system (default: "")
 
 ;==========================GLOBAL SECTION OPTIONS=========================
diff --git a/res/res_pjsip.c b/res/res_pjsip.c
index 65466bfa44ed57921b0658950eaa5598291f5ef1..d350cdbe9ce591ff6dc81218a0c89d108c72cc92 100644
--- a/res/res_pjsip.c
+++ b/res/res_pjsip.c
@@ -1143,7 +1143,7 @@
 					<synopsis>Maximum number of threads in the res_pjsip threadpool.
 					A value of 0 indicates no maximum.</synopsis>
 				</configOption>
-				<configOption name="disable_tcp_switch" default="no">
+				<configOption name="disable_tcp_switch" default="yes">
 					<synopsis>Disable automatic switching from UDP to TCP transports.</synopsis>
 					<description><para>
 						Disable automatic switching from UDP to TCP transports if outgoing
diff --git a/res/res_pjsip/config_system.c b/res/res_pjsip/config_system.c
index 4d0ab467b5f5e2fba55a2ef975ceb5ef11085517..a41af90ed2b540cc690ae52ae054d5344192682f 100644
--- a/res/res_pjsip/config_system.c
+++ b/res/res_pjsip/config_system.c
@@ -147,7 +147,7 @@ int ast_sip_initialize_system(void)
 			OPT_UINT_T, 0, FLDSET(struct system_config, threadpool.idle_timeout));
 	ast_sorcery_object_field_register(system_sorcery, "system", "threadpool_max_size", "0",
 			OPT_UINT_T, 0, FLDSET(struct system_config, threadpool.max_size));
-	ast_sorcery_object_field_register(system_sorcery, "system", "disable_tcp_switch", "no",
+	ast_sorcery_object_field_register(system_sorcery, "system", "disable_tcp_switch", "yes",
 			OPT_BOOL_T, 1, FLDSET(struct system_config, disable_tcp_switch));
 
 	ast_sorcery_load(system_sorcery);