diff --git a/README.md b/README.md
index a980e0a..dca5b8f 100644
--- a/README.md
+++ b/README.md
@@ -3,7 +3,7 @@ Puget
 
 [![Build Status](https://travis-ci.org/greglook/puget.svg?branch=master)](https://travis-ci.org/greglook/puget)
 [![Coverage Status](https://coveralls.io/repos/greglook/puget/badge.png?branch=master)](https://coveralls.io/r/greglook/puget?branch=master)
-[![Dependency Status](https://www.versioneye.com/user/projects/53718bfb14c1589a89000144/badge.png)](https://www.versioneye.com/clojure/mvxcvi:puget/0.6.3)
+[![Dependency Status](https://www.versioneye.com/user/projects/53718bfb14c1589a89000144/badge.png)](https://www.versioneye.com/clojure/mvxcvi:puget/0.6.4)
 
 Puget is a Clojure library for printing [EDN](https://github.com/edn-format/edn)
 values. Under the hood, Puget formats data into a _print document_ and uses the
diff --git a/project.clj b/project.clj
index 9e15b52..7f5c9b8 100644
--- a/project.clj
+++ b/project.clj
@@ -1,4 +1,4 @@
-(defproject mvxcvi/puget "0.6.3"
+(defproject mvxcvi/puget "0.6.4"
   :description "Colorizing canonical Clojure printer for EDN values."
   :url "https://github.com/greglook/puget"
   :license {:name "Public Domain"
diff --git a/src/puget/printer.clj b/src/puget/printer.clj
index d3439bb..c74a0ec 100644
--- a/src/puget/printer.clj
+++ b/src/puget/printer.clj
@@ -277,6 +277,18 @@
    (color-doc :symbol (subs (str value) 2))])
 
 
+(defmethod canonize clojure.lang.IDeref
+  [value]
+  (illegal-when-strict value)
+  [:span
+   (color-doc :class-delimiter "#<")
+   (color-doc :class-name (.getName (class value)))
+   (color-doc :class-delimiter "@")
+   (system-id value) " "
+   (canonize @value)
+   (color-doc :class-delimiter ">")])
+
+
 (defmethod canonize clojure.lang.Atom
   [value]
   (illegal-when-strict value)
@@ -289,6 +301,20 @@
    (color-doc :class-delimiter ">")])
 
 
+(defmethod canonize clojure.lang.IPending
+  [value]
+  (illegal-when-strict value)
+  [:span
+   (color-doc :class-delimiter "#<")
+   (color-doc :class-name (.getName (class value)))
+   (color-doc :class-delimiter "@")
+   (system-id value) " "
+   (if (realized? value)
+     (canonize @value)
+     (color-doc :nil "pending"))
+   (color-doc :class-delimiter ">")])
+
+
 (defmethod canonize clojure.lang.Delay
   [value]
   (illegal-when-strict value)
@@ -317,6 +343,12 @@
    (color-doc :class-delimiter ">")])
 
 
+(prefer-method canonize clojure.lang.ISeq clojure.lang.IPending)
+(prefer-method canonize clojure.lang.IPending clojure.lang.IDeref)
+(prefer-method canonize java.util.concurrent.Future clojure.lang.IDeref)
+(prefer-method canonize java.util.concurrent.Future clojure.lang.IPending)
+
+
 
 ;;;;; OTHER TYPES ;;;;;
 
diff --git a/test/puget/printer_test.clj b/test/puget/printer_test.clj
index f82f11c..9352f56 100644
--- a/test/puget/printer_test.clj
+++ b/test/puget/printer_test.clj
@@ -63,8 +63,17 @@
       (is (= "#puget.printer_test.TestRecord{:bar \\y, :foo \\x}\n"
              (with-out-str (pprint r)))))))
 
+(deftype ADeref []
+  clojure.lang.IDeref
+  (deref [this] 123))
+
+(deftype APending []
+  clojure.lang.IPending
+  (isRealized [this] false))
 
 (deftest clojure-types
+  (testing "seq"
+    (is (= "()" (pprint-str (lazy-seq)))))
   (testing "regex"
     (let [v #"\d+"]
       (should-fail-when-strict v)
@@ -89,7 +98,18 @@
       (should-fail-when-strict v)
       (is (re-seq #"#<Future@[0-9a-f]+ pending>" (pprint-str v)))
       (is (= :done @v))
-      (is (re-seq #"#<Future@[0-9a-f]+ :done>" (pprint-str v))))))
+      (is (re-seq #"#<Future@[0-9a-f]+ :done>" (pprint-str v)))))
+  (testing "custom IDeref"
+    (let [v (ADeref.)]
+      (should-fail-when-strict v)
+      (is (re-seq #"#<puget.printer_test.ADeref@[0-9a-f]+ 123>"
+                  (pprint-str v)))))
+  (testing "custom IPending"
+    (let [v (APending.)]
+      (should-fail-when-strict v)
+      (is (re-seq #"#<puget.printer_test.APending@[0-9a-f]+ pending"
+                  (pprint-str v)))))
+  )
 
 
 (deftest canonical-tagged-value