diff --git a/src/koans/maps.clj b/src/koans/maps.clj
index 9d53151..4bc0e2e 100644
--- a/src/koans/maps.clj
+++ b/src/koans/maps.clj
@@ -3,13 +3,13 @@
   (= {} (hash-map))
 
   "Maps in clojure associate keys with values"
-  (= __ (.size (hash-map)))
+  (= __ (count (hash-map)))
 
   "A value must be supplied for each key"
   (= {:a 1} (hash-map :a __))
 
   "The size is the number of entries"
-  (= __ (.size {:a 1 :b 2}))
+  (= __ (count {:a 1 :b 2}))
 
   "You can look up the value for a given key"
   (= __ (get {:a 1 :b 2} :b))
diff --git a/src/koans/sets.clj b/src/koans/sets.clj
index 0823c3a..60a6575 100644
--- a/src/koans/sets.clj
+++ b/src/koans/sets.clj
@@ -3,7 +3,7 @@
   (= #{} (set nil))
 
   "They are another important data structure in clojure"
-  (= __ (.size #{}))
+  (= __ (count #{1 2 3}))
 
   "Remember that a set is a 'set'"
   (= __ (set '(1 1 2 2 3 3 4 4 5 5)))
diff --git a/src/koans/vectors.clj b/src/koans/vectors.clj
index b0500f3..b1b97ea 100644
--- a/src/koans/vectors.clj
+++ b/src/koans/vectors.clj
@@ -1,6 +1,6 @@
 (meditations
   "You can use vectors in clojure to create an 'Array' like structure"
-  (= __ (.size []))
+  (= __ (count [42]))
 
   "You can create a vector in several ways"
   (= __ (vec nil))
diff --git a/src/path_to_answer_sheet.clj b/src/path_to_answer_sheet.clj
index 00b13da..4a84227 100644
--- a/src/path_to_answer_sheet.clj
+++ b/src/path_to_answer_sheet.clj
@@ -21,7 +21,7 @@
                   [:b :c :d :e]
                   "\"No dice!\""
                   "()"]}
-   "vectors" {"__" [0
+   "vectors" {"__" [1
                     []
                     [1]
                     [nil]
@@ -31,7 +31,7 @@
                     :jelly
                     :jelly
                     [:butter :and]]}
-   "sets" {"__" [0
+   "sets" {"__" [3
                  #{1 2 3 4 5}
                  #{1 2 3 4 5}
                  #{2 3}