diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..ef70cd3
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,24 @@
+#=============================================================================
+UUID=window_buttons@biox.github.com
+FILES=metadata.json *.js stylesheet.css schemas themes
+#=============================================================================
+default_target: all
+.PHONY: clean all zip
+
+clean:
+	@rm -f $(UUID).zip $(UUID)/schemas/gschemas.compiled
+
+# compile the schemas
+all: clean
+	@if [ -d $(UUID)/schemas ]; then \
+		glib-compile-schemas $(UUID)/schemas; \
+	fi
+
+# to put on the Downloads page
+zip: all
+	zip -rq $(UUID).zip $(FILES:%=$(UUID)/%)
+
+# to upload to e.g.o
+dev-zip: all
+	(cd $(UUID); \
+		zip -rq ../$(UUID).zip $(FILES))
diff --git a/icon.png b/icon.png
new file mode 100644
index 0000000..c42ff09
Binary files /dev/null and b/icon.png differ
diff --git a/window_buttons@biox.github.com/extension.js b/window_buttons@biox.github.com/extension.js
index 0ad51db..df433d2 100644
--- a/window_buttons@biox.github.com/extension.js
+++ b/window_buttons@biox.github.com/extension.js
@@ -384,7 +384,8 @@ WindowButtons.prototype = {
         let windows = workspace.list_windows();
         let maxwin = false;
         for (let i = windows.length - 1; i >= 0; --i) {
-            if (windows[i].get_maximized() && !windows[i].minimized) {
+            if (windows[i].get_maximized() === Meta.MaximizeFlags.BOTH &&
+                    !windows[i].minimized) {
                 maxwin = windows[i];
                 break;
             }
@@ -401,7 +402,7 @@ WindowButtons.prototype = {
             uppermost.minimize();
         } else {
             // If the active window is maximized, minimize it
-            if (activeWindow.get_maximized()) {
+            if (activeWindow.get_maximized() === Meta.MaximizeFlags.BOTH) {
                 activeWindow.minimize();
             // If the active window is not maximized, minimize the uppermost
             // maximized window if the option to only control maximized windows
@@ -433,7 +434,7 @@ WindowButtons.prototype = {
             uppermost.activate(global.get_current_time());
         } else {
             // If the active window is maximized, unmaximize it
-            if (activeWindow.get_maximized()) {
+            if (activeWindow.get_maximized() === Meta.MaximizeFlags.BOTH) {
                 activeWindow.unmaximize(Meta.MaximizeFlags.BOTH);
             // If the active window is not maximized, unmaximize the uppermost
             // maximized window if the option to only control maximized windows
@@ -462,7 +463,7 @@ WindowButtons.prototype = {
             uppermost.delete(global.get_current_time());
         } else {
             // If the active window is maximized, close it
-            if (activeWindow.get_maximized()) {
+            if (activeWindow.get_maximized() === Meta.MaximizeFlags.BOTH) {
                 activeWindow.delete(global.get_current_time());
             // If the active window is not maximized, close the uppermost
             // maximized window if the option to only control maximized windows