diff --git a/common/src/app/common/geom/matrix.cljc b/common/src/app/common/geom/matrix.cljc
index b8e5a761ea..695925bf94 100644
--- a/common/src/app/common/geom/matrix.cljc
+++ b/common/src/app/common/geom/matrix.cljc
@@ -36,7 +36,7 @@
     (apply matrix params)))
 
 (defn multiply
-  ([m1 m2]
+  ([^Matrix m1 ^Matrix m2]
    (let [m1a (.-a m1)
          m1b (.-b m1)
          m1c (.-c m1)