diff --git a/bin/named/include/named/globals.h b/bin/named/include/named/globals.h
index 3b6e8d7d65..c923d7c6e5 100644
--- a/bin/named/include/named/globals.h
+++ b/bin/named/include/named/globals.h
@@ -143,6 +143,7 @@ EXTERN bool named_g_memstatistics INIT(false);
 EXTERN bool named_g_keepstderr	  INIT(false);
 
 EXTERN unsigned int named_g_tat_interval INIT(24 * 3600);
+EXTERN unsigned int named_g_maxcachesize INIT(0);
 
 #if defined(HAVE_GEOIP2)
 EXTERN dns_geoip_databases_t *named_g_geoip INIT(NULL);
diff --git a/bin/named/main.c b/bin/named/main.c
index b369eed069..d6b7154246 100644
--- a/bin/named/main.c
+++ b/bin/named/main.c
@@ -650,6 +650,8 @@ parse_T_opt(char *option) {
 		named_g_nosyslog = true;
 	} else if (!strcmp(option, "notcp")) {
 		notcp = true;
+	} else if (!strncmp(option, "maxcachesize=", 13)) {
+		named_g_maxcachesize = atoi(option + 13);
 	} else if (!strcmp(option, "maxudp512")) {
 		maxudp = 512;
 	} else if (!strcmp(option, "maxudp1460")) {
diff --git a/bin/named/server.c b/bin/named/server.c
index 547df1147a..ec66cbcc9e 100644
--- a/bin/named/server.c
+++ b/bin/named/server.c
@@ -4114,7 +4114,16 @@ configure_view(dns_view_t *view, dns_viewlist_t *viewlist, cfg_obj_t *config,
 	obj = NULL;
 	result = named_config_get(maps, "max-cache-size", &obj);
 	INSIST(result == ISC_R_SUCCESS);
-	if (cfg_obj_isstring(obj)) {
+	/*
+	 * If "-T maxcachesize=..." is in effect, it overrides any other
+	 * "max-cache-size" setting found in configuration, either implicit or
+	 * explicit.  For simplicity, the value passed to that command line
+	 * option is always treated as the number of bytes to set
+	 * "max-cache-size" to.
+	 */
+	if (named_g_maxcachesize != 0) {
+		max_cache_size = named_g_maxcachesize;
+	} else if (cfg_obj_isstring(obj)) {
 		str = cfg_obj_asstring(obj);
 		INSIST(strcasecmp(str, "unlimited") == 0);
 		max_cache_size = 0;