diff --git a/src/main/clojure/clojure/data/json.clj b/src/main/clojure/clojure/data/json.clj
index dbf8282..ec23180 100644
--- a/src/main/clojure/clojure/data/json.clj
+++ b/src/main/clojure/clojure/data/json.clj
@@ -202,7 +202,7 @@
   (let [sb (StringBuilder. ^Integer (count s))]
     (.append sb \")
     (dotimes [i (count s)]
-      (let [cp (Character/codePointAt s i)]
+      (let [cp (int (.charAt s i))]
         (cond
          ;; Handle printable JSON escapes before ASCII
          (= cp 34) (.append sb "\\\"")
diff --git a/src/test/clojure/clojure/data/json_test.clj b/src/test/clojure/clojure/data/json_test.clj
index 1805928..e3555cf 100644
--- a/src/test/clojure/clojure/data/json_test.clj
+++ b/src/test/clojure/clojure/data/json_test.clj
@@ -27,6 +27,12 @@
 (deftest handles-unicode-escapes
   (is (= " \u0beb " (read-json "\" \\u0bEb \""))))
 
+(deftest handles-unicode-outside-bmp
+  (is (= "\"smiling face: \uD83D\uDE03\""
+         (json-str "smiling face: \uD83D\uDE03" :escape-unicode false)))
+  (is (= "\"smiling face: \\ud83d\\ude03\""
+         (json-str "smiling face: \uD83D\uDE03" :escape-unicode true))))
+
 (deftest handles-escaped-whitespace
   (is (= "foo\nbar" (read-json "\"foo\\nbar\"")))
   (is (= "foo\rbar" (read-json "\"foo\\rbar\"")))