diff --git a/gson/src/main/java/com/google/gson/internal/bind/util/ISO8601Utils.java b/gson/src/main/java/com/google/gson/internal/bind/util/ISO8601Utils.java
index c931b090..99ec679a 100644
--- a/gson/src/main/java/com/google/gson/internal/bind/util/ISO8601Utils.java
+++ b/gson/src/main/java/com/google/gson/internal/bind/util/ISO8601Utils.java
@@ -266,7 +266,7 @@ public class ISO8601Utils
         } catch (IllegalArgumentException e) {
             fail = e;
         }
-        String input = (date == null) ? null : ('"' + date + "'");
+        String input = (date == null) ? null : ('"' + date + '"');
         String msg = fail.getMessage();
         if (msg == null || msg.isEmpty()) {
             msg = "("+fail.getClass().getName()+")";