diff --git a/java/src/processing/mode/java/JavaBuild.java b/java/src/processing/mode/java/JavaBuild.java
index 57cf23de1..0f2cde1ba 100755
--- a/java/src/processing/mode/java/JavaBuild.java
+++ b/java/src/processing/mode/java/JavaBuild.java
@@ -1135,7 +1135,14 @@ public class JavaBuild {
     // https://github.com/processing/processing/issues/2239
     runOptions.add("-Djna.nosys=true");
     // https://github.com/processing/processing/issues/4608
-    runOptions.add("-Djava.ext.dirs=%EXEDIR%/java/lib/ext");
+    if (exportPlatform == PConstants.MACOSX) {
+      runOptions.add("-Djava.ext.dirs=$APP_ROOT/Contents/PlugIns/jdk" + PApplet.javaVersionName + ".jdk/Contents/Home/jre/lib/ext");
+    } else if (exportPlatform == PConstants.WINDOWS) {
+      runOptions.add("-Djava.ext.dirs=%EXEDIR%/java/lib/ext");
+    } else if (exportPlatform == PConstants.LINUX) {
+      runOptions.add("-Djava.ext.dirs=$APPDIR/java/lib/ext");
+    }
+
     // https://github.com/processing/processing/issues/2559
     if (exportPlatform == PConstants.WINDOWS) {
       runOptions.add("-Djava.library.path=\"%EXEDIR%\\lib\"");
diff --git a/todo.txt b/todo.txt
index e11dadbab..d9aa93ca1 100755
--- a/todo.txt
+++ b/todo.txt
@@ -15,6 +15,9 @@ X   modify ext.dirs for exported apps on Windows
 X see if CLASSPATH can be set to screw up p5
 X   works fine on OS X, couldn't reproduce on Linux
 X rewrite Util.listFiles() because it wasn't working properly
+X add 2016 to about-1x and about-2x
+
+_ saying "no" to save changes is the same as "cancel" on windows?
 
 mode work
 X add template support for Modes
@@ -92,6 +95,8 @@ _ hi-dpi support on Linux
 _   https://github.com/processing/processing/issues/4183
 _ PDE and sketches are 2x smaller on high-res Windows machines
 _   https://github.com/processing/processing/issues/2411
+_   System.setProperty("sun.java2d.dpiaware", "false");
+_   though that seems broken in Java 8: http://superuser.com/a/1007783
 
 _ Library path mismatch between processing-java and export
 _   https://github.com/processing/processing/issues/4493
@@ -123,8 +128,6 @@ _ setting a bad font/size causes a crash on startup
 _   https://github.com/processing/processing/issues/4085
 o   https://github.com/processing/processing/pull/4087
 
-_ add 2016 to about-1x and about-2x
-
 
 more contribs
 _ question about PDE_pt-br instead of PDE_pt