diff --git a/CHANGES.md b/CHANGES.md
index 0f54829..8114222 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,11 @@
+## 0.5.7
+* Fix bug in select-one! which wouldn't allow nil result
+
+## 0.5.6
+* Add multi-path implementation
+* change FIRST/LAST to select nothing on an empty sequence
+* Allow sets to be used directly as selectors (acts as filter)
+
 ## 0.5.5
 * Change filterer to accept a selector (that acts like selected? to determine whether or not to select value)
 
diff --git a/VERSION b/VERSION
index d1d899f..d3532a1 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.5
+0.5.7
diff --git a/src/com/rpl/specter.cljc b/src/com/rpl/specter.cljc
index 1719e04..0f97fb2 100644
--- a/src/com/rpl/specter.cljc
+++ b/src/com/rpl/specter.cljc
@@ -38,9 +38,9 @@
 (defn compiled-select-one!
   "Version of select-one! that takes in a selector pre-compiled with comp-paths"
   [selector structure]
-  (let [res (compiled-select-one selector structure)]
-    (when (nil? res) (i/throw-illegal "No elements found for params: " selector structure))
-    res
+  (let [res (compiled-select selector structure)]
+    (when (not= 1 (count res)) (i/throw-illegal "Expected exactly one element for params: " selector structure))
+    (first res)
     ))
 
 (defn select-one!
@@ -114,9 +114,9 @@
 
 (def VAL (i/->ValCollect))
 
-(def LAST (i/->LastStructurePath))
+(def LAST (i/->PosStructurePath last set-last))
 
-(def FIRST (i/->FirstStructurePath))
+(def FIRST (i/->PosStructurePath first set-first))
 
 (defn srange-dynamic [start-fn end-fn] (i/->SRangePath start-fn end-fn))
 
@@ -159,12 +159,16 @@
 (extend-type #?(:clj clojure.lang.AFn :cljs js/Function)
   StructurePath
   (select* [afn structure next-fn]
-    (if (afn structure)
-      (next-fn structure)))
+    (i/filter-select afn structure next-fn))
   (transform* [afn structure next-fn]
-    (if (afn structure)
-      (next-fn structure)
-      structure)))
+    (i/filter-transform afn structure next-fn)))
+
+(extend-type #?(:clj clojure.lang.PersistentHashSet :cljs cljs.core/PersistentHashSet)
+  StructurePath
+  (select* [aset structure next-fn]
+    (i/filter-select aset structure next-fn))
+  (transform* [aset structure next-fn]
+    (i/filter-transform aset structure next-fn)))
 
 (defn collect [& selector]
   (i/->SelectCollector select (comp-paths* selector)))
diff --git a/src/com/rpl/specter/impl.cljc b/src/com/rpl/specter/impl.cljc
index f777f77..efeecab 100644
--- a/src/com/rpl/specter/impl.cljc
+++ b/src/com/rpl/specter/impl.cljc
@@ -460,23 +460,17 @@
   (collect-val [this structure]
     structure))
 
-(deftype LastStructurePath [])
+(deftype PosStructurePath [getter setter])
 
 (extend-protocol p/StructurePath
-  LastStructurePath
+  PosStructurePath
   (select* [this structure next-fn]
-    (next-fn (last structure)))
+    (if-not (empty? structure)
+      (next-fn ((field this 'getter) structure))))
   (transform* [this structure next-fn]
-    (set-last structure (next-fn (last structure)))))
-
-(deftype FirstStructurePath [])
-
-(extend-protocol p/StructurePath
-  FirstStructurePath
-  (select* [this structure next-fn]
-    (next-fn (first structure)))
-  (transform* [this structure next-fn]
-    (set-first structure (next-fn (first structure)))))
+    (if (empty? structure)
+      structure
+      ((field this 'setter) structure (next-fn ((field this 'getter) structure))))))
 
 (deftype WalkerStructurePath [afn])
 
@@ -624,3 +618,12 @@
       (field this 'paths))
     ))
 
+(defn filter-select [afn structure next-fn]
+  (if (afn structure)
+    (next-fn structure)))
+
+(defn filter-transform [afn structure next-fn]
+  (if (afn structure)
+    (next-fn structure)
+    structure))
+
diff --git a/test/com/rpl/specter/core_test.clj b/test/com/rpl/specter/core_test.clj
index 00d857e..ca07fbf 100644
--- a/test/com/rpl/specter/core_test.clj
+++ b/test/com/rpl/specter/core_test.clj
@@ -361,3 +361,24 @@
             (transform k1 inc)
             (transform k2 inc)))
     ))
+
+(deftest empty-pos-transform
+  (is (empty? (select FIRST [])))
+  (is (empty? (select LAST [])))
+  (is (= [] (transform FIRST inc [])))
+  (is (= [] (transform LAST inc [])))
+  )
+
+(defspec set-filter-test
+  (for-all+
+    [k1 gen/keyword
+     k2 (gen/such-that #(not= k1 %) gen/keyword)
+     k3 (gen/such-that (complement #{k1 k2}) gen/keyword)
+     v (gen/vector (gen/elements [k1 k2 k3]))]
+    (= (filter #{k1 k2} v) (select [ALL #{k1 k2}] v))
+    ))
+
+(deftest nil-select-one-test
+  (is (= nil (select-one! ALL [nil])))
+  (is (thrown? Exception (select-one! ALL [])))
+  )