diff --git a/app/src/processing/mode/java/preproc/PdePreprocessor.java b/app/src/processing/mode/java/preproc/PdePreprocessor.java
index 542bbfd8c..f70ff4bfe 100644
--- a/app/src/processing/mode/java/preproc/PdePreprocessor.java
+++ b/app/src/processing/mode/java/preproc/PdePreprocessor.java
@@ -950,6 +950,7 @@ public class PdePreprocessor {
     return new String[] { 
       "java.util.HashMap",
       "java.util.ArrayList",
+      "java.io.File",
       "java.io.BufferedReader",
       "java.io.PrintWriter",
       "java.io.InputStream",