Index: trunk/resources/data/validator/combinations.mapcss
===================================================================
--- trunk/resources/data/validator/combinations.mapcss	(revision 17249)
+++ trunk/resources/data/validator/combinations.mapcss	(revision 17253)
@@ -878,12 +878,13 @@
 
 /* #19980 */
-way[highway=living_street][maxspeed][get(split(" ", tag(maxspeed)), 0) > 20] {
+way[highway=living_street][maxspeed][maxspeed=~/mph/][get(split(" ", tag(maxspeed)), 0) > 15],
+way[highway=living_street][maxspeed][maxspeed!~/mph/][get(split(" ", tag(maxspeed)), 0) > 20] {
   throwWarning: tr("{0} together with {1}", "{0.tag}", "{1.tag}");
   group: tr("suspicious tag combination");
   assertNoMatch: "way highway=living_street";
   assertNoMatch: "way highway=living_street maxspeed=20";
-  assertNoMatch: "way highway=living_street maxspeed=\"20 mph\"";
+  assertNoMatch: "way highway=living_street maxspeed=\"15 mph\"";
   assertNoMatch: "way highway=living_street maxspeed=walk";
   assertMatch: "way highway=living_street maxspeed=30";
-  assertMatch: "way highway=living_street maxspeed=\"30 mph\"";
-}
+  assertMatch: "way highway=living_street maxspeed=\"20 mph\"";
+}