diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 12b6d25cb7b5a2d2222b40617405848b64d0a8eb..f5d8180fcdc0c568539088289a92037fc42195a9 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -21929,6 +21929,14 @@ static struct sip_peer *build_peer(const char *name, struct ast_variable *v, str
 				ast_log(LOG_WARNING, "Qualification of peer '%s' should be 'yes', 'no', or a number of milliseconds at line %d of sip.conf\n", peer->name, v->lineno);
 				peer->maxms = 0;
 			}
+			if (realtime && !ast_test_flag(&global_flags[1], SIP_PAGE2_RTCACHEFRIENDS) && peer->maxms > 0) {
+				/* This would otherwise cause a network storm, where the
+				 * qualify response refreshes the peer from the database,
+				 * which in turn causes another qualify to be sent, ad
+				 * infinitum. */
+				ast_log(LOG_WARNING, "Qualify is incompatible with dynamic uncached realtime.  Please either turn rtcachefriends on or turn qualify off on peer '%s'\n", peer->name);
+				peer->maxms = 0;
+			}
 		} else if (!strcasecmp(v->name, "qualifyfreq")) {
 			int i;
 			if (sscanf(v->value, "%d", &i) == 1)