diff --git a/src/clj/com/rpl/specter/impl.cljc b/src/clj/com/rpl/specter/impl.cljc
index f4e5096..3ee7ca9 100644
--- a/src/clj/com/rpl/specter/impl.cljc
+++ b/src/clj/com/rpl/specter/impl.cljc
@@ -28,7 +28,7 @@
     (pr-str o)
     (str o)))
 
-(defn smart-str [& elems]
+(defn ^String smart-str [& elems]
   (apply str (map smart-str* elems)))
 
 (defn fast-constantly [v]
diff --git a/src/clj/com/rpl/specter/navs.cljc b/src/clj/com/rpl/specter/navs.cljc
index 271ff8d..a0217cf 100644
--- a/src/clj/com/rpl/specter/navs.cljc
+++ b/src/clj/com/rpl/specter/navs.cljc
@@ -130,9 +130,9 @@
                   (recur (+ i 2) (+ j 2)))))))
          (let [none-count (i/get-cell none-cell)
                array (if (not= 0 none-count)
-                        (java.util.Arrays/copyOf array (* 2 (- len none-count)))
-                        array
-                        )]
+                       (java.util.Arrays/copyOf array (int (* 2 (- len none-count))))
+                       array
+                       )]
           (clojure.lang.PersistentArrayMap/createAsIfByAssoc array)))))
 
 
@@ -246,7 +246,7 @@
                   (recur (+ i 2) (+ j 2)))))))
          (let [none-count (i/get-cell none-cell)
                array (if (not= 0 none-count)
-                        (java.util.Arrays/copyOf array (* 2 (- len none-count)))
+                        (java.util.Arrays/copyOf array (int (* 2 (- len none-count))))
                         array
                         )]
           (clojure.lang.PersistentArrayMap. array)))))