diff --git a/build.sh b/build.sh
index 22587c1..9fad3a3 100755
--- a/build.sh
+++ b/build.sh
@@ -37,6 +37,7 @@ elif [ "$machine" = "Linux" ]; then
   exit 0
 elif [ "$machine" = "unix" ]; then
   ICON=src/icons/windowsUIToopie2.png
+  export EXTRA="    public final static String EXTRA = \"-unix\";"
 fi
 
 . "$SCRIPT_DIR/launcher.sh"
diff --git a/java/net/i2p/router/WinLauncher.java b/java/net/i2p/router/WinLauncher.java
index 159ebe2..cfea070 100644
--- a/java/net/i2p/router/WinLauncher.java
+++ b/java/net/i2p/router/WinLauncher.java
@@ -88,7 +88,9 @@ public class WinLauncher extends CopyConfigDir {
     File programs = programFile();
     File home = homeDir();
 
-    System.setProperty("i2p.dir.base", new File(programs.getAbsolutePath(), "config").getAbsolutePath());
+    System.setProperty(
+        "i2p.dir.base",
+        new File(programs.getAbsolutePath(), "config").getAbsolutePath());
     System.setProperty("i2p.dir.config", home.getAbsolutePath());
     System.setProperty("router.pid",
                        String.valueOf(ProcessHandle.current().pid()));
diff --git a/launcher.sh b/launcher.sh
index 42eb332..33dd2a6 100755
--- a/launcher.sh
+++ b/launcher.sh
@@ -43,6 +43,11 @@ if [ ! -d "$HERE/../i2p.i2p.jpackage-build/" ]; then
   git clone --depth=1 -b "$VERSION" https://i2pgit.org/i2p-hackers/i2p.i2p "$HERE/../i2p.i2p.jpackage-build/"
 fi
 cd "$HERE/../i2p.i2p.jpackage-build/"
+OLDEXTRA=$(find . -name RouterVersion.java -exec grep 'String EXTRA' {} \;)
+if [ -z $EXTRA ]; then
+  export EXTRA="    public final static String EXTRA = \"-win\";"
+fi
+find . -name RouterVersion.java -exec sed -i "s|$OLDEXTRA|$EXTRA|g" {} \;
 git pull --tags
 git archive --format=tar.gz --output="$HERE/../i2p.firefox/i2p.i2p.jpackage-build.tar.gz" "$VERSION"
 for i in $COUNT; do