diff --git a/app/controllers/concerns/utm_tracking.rb b/app/controllers/concerns/utm_tracking.rb
index c6c706d..dba7544 100644
--- a/app/controllers/concerns/utm_tracking.rb
+++ b/app/controllers/concerns/utm_tracking.rb
@@ -6,6 +6,8 @@
 # posts to game#start. The tags are therefore parked in the session on the way
 # in and read back out when the player is created.
 #
+# Matomo-style mtm_* parameters are accepted as aliases for the utm_* ones.
+#
 # Last touch wins: a second scan is a second visit, and the player row that
 # follows it belongs to the code that was actually scanned.
 module UtmTracking
@@ -22,7 +24,9 @@ private
 
 
   def capture_utm
-    tags = Player::UTM_KEYS.index_with { |key| clean_utm(params[key]) }.compact
+    tags = Player::UTM_KEYS.index_with { |key|
+             clean_utm(params[key].presence || params[key.to_s.sub("utm_", "mtm_")])
+           }.compact
     return if tags.empty?
 
     # String keys: the session round-trips through the cookie, which has no