diff -ruN processing4-git/build/build.xml processing4-git-patched/build/build.xml
--- processing4/build/build.xml	2022-01-31 13:24:21.300634689 +0100
+++ processing4-patched/build/build.xml	2022-01-31 13:25:53.194256000 +0100
@@ -369,7 +369,7 @@
     </condition>
 
     <!--<echo message="ref ignoreable? ${reference.ignorable}" />-->
-    <get src="http://download.processing.org/reference.zip"
+    <get src="https://download.processing.org/reference.zip"
          dest="../java/reference.zip"
          ignoreerrors="${reference.ignorable}"
          usetimestamp="true" />
diff -ruN processing4-git/java/libraries/io/build.xml processing4-git-patched/java/libraries/io/build.xml
--- processing4/java/libraries/io/build.xml	2022-01-31 13:24:21.483968605 +0100
+++ processing4-patched/java/libraries/io/build.xml	2022-01-31 13:25:06.487444000 +0100
@@ -43,7 +43,7 @@
     <replaceregexp file="library.properties" match="version = .*" replace="version = ${revision}" flags="g" />
     <replaceregexp file="library.properties" match="prettyVersion = .*" replace="prettyVersion = ${revision}" flags="g" />
 
-    <get src="http://download.processing.org/reference.zip"
+    <get src="https://download.processing.org/reference.zip"
          dest="reference.zip"
          usetimestamp="true" />
     <mkdir dir="reference" />