diff --git a/java/src/processing/mode/java/AutoFormat.java b/java/src/processing/mode/java/AutoFormat.java
index bb2e5bad1..4b0b4b9bc 100644
--- a/java/src/processing/mode/java/AutoFormat.java
+++ b/java/src/processing/mode/java/AutoFormat.java
@@ -732,7 +732,7 @@ public class AutoFormat implements Formatter {
       case ':':
         // Java 8 :: operator.
         if (peek() == ':') {
-          result.append(c).append(nextChar());
+          buf.append(c).append(nextChar());
           break;
         }